0001656423-23-000013 | 10-K | XBRL Viewer

Debt

12 Months Ended

Dec. 31, 2022

7. Debt

Mortgage Notes Payable

The Company had outstanding mortgage notes payable totaling approximately $3.3 billion as of December 31, 2022 and 2021, each collateralized by one or more buildings and related land included in real estate assets. The mortgage notes payable are generally due in monthly installments and mature at various dates through January 9, 2032.

Fixed rate mortgage notes payable totaled approximately $3.3 billion at December 31, 2022 and 2021, with contractual interest rates ranging from 2.79% to 3.43% per annum at December 31, 2022 and 2021 (with a weighted-average interest rate of 3.24% at December 31, 2022 and 2021). There were no variable rate mortgage loans at December 31, 2022 and 2021.

Contractual aggregate principal payments of mortgage notes payable at December 31, 2022 are as follows (dollars in thousands):


	Principal Payments
2023	$	—
2024	—
2025	—
2026	—
2027	2,300,000
Thereafter	1,000,000
Total aggregate principal payments	3,300,000
Less:
Deferred financing costs, net	27,632
Total carrying value of mortgage notes payable, net	$	3,272,368

Unsecured Debt Disclosure

Unsecured Senior Notes

The following summarizes the unsecured senior notes outstanding as of December 31, 2022 (dollars in thousands):


	Coupon/Stated Rate		Effective Rate(1)		Principal Amount		Maturity Date(2)
10.5 Year Unsecured Senior Notes	3.125	%	3.279	%	$	500,000	September 1, 2023
10.5 Year Unsecured Senior Notes	3.800	%	3.916	%	700,000		February 1, 2024
7 Year Unsecured Senior Notes	3.200	%	3.350	%	850,000		January 15, 2025
10 Year Unsecured Senior Notes	3.650	%	3.766	%	1,000,000		February 1, 2026
10 Year Unsecured Senior Notes	2.750	%	3.495	%	1,000,000		October 1, 2026
5 Year Unsecured Senior Notes	6.750	%	6.924	%	750,000		December 1, 2027
10 Year Unsecured Senior Notes	4.500	%	4.628	%	1,000,000		December 1, 2028
10 Year Unsecured Senior Notes	3.400	%	3.505	%	850,000		June 21, 2029
10.5 Year Unsecured Senior Notes	2.900	%	2.984	%	700,000		March 15, 2030
10.75 Year Unsecured Senior Notes	3.250	%	3.343	%	1,250,000		January 30, 2031
11 Year Unsecured Senior Notes	2.550	%	2.671	%	850,000		April 1, 2032
12 Year Unsecured Senior Notes	2.450	%	2.524	%	850,000		October 1, 2033
Total principal					10,300,000
Less:
Net unamortized discount					14,094
Deferred financing costs, net					47,938
Total					$	10,237,968

_______________

(1)Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.

(2)No principal amounts are due prior to maturity.

On November 17, 2022, BPLP completed a public offering of $750.0 million in aggregate principal amount of its 6.750% unsecured senior notes due 2027. The notes were priced at 99.941% of the principal amount to yield an effective rate (including financing fees) of approximately 6.924% per annum to maturity. The notes will mature on December 1, 2027, unless earlier redeemed. The aggregate net proceeds from the offering were approximately $743.5 million after deducting underwriting discounts and transaction expenses.

The indenture relating to the unsecured senior notes contains certain financial restrictions and requirements, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 50%, (3) an interest coverage ratio of greater than 1.50, and (4) an unencumbered asset value of not less than 150% of unsecured debt. At December 31, 2022, BPLP was in compliance with each of these financial restrictions and requirements.

Unsecured Credit Facility

On June 15, 2021, BPLP amended and restated its prior credit facility (as amended and restated, the “2021 Credit Facility”). The 2021 Credit Facility provides for borrowings of up to $1.5 billion through the Revolving Facility, subject to customary conditions. Among other things, the 2021 Credit Facility (1) extended the maturity date from April 24, 2022 to June 15, 2026, (2) eliminated the $500.0 million delayed draw facility, (3) reduced the per annum variable interest rates on borrowings and (4) added a sustainability-linked pricing component. Under the 2021 Credit Facility, BPLP may increase the total commitment by up to $500.0 million by increasing the amount of the Revolving Facility and/or by incurring one or more term loans, in each case, subject to syndication of the increase and other conditions.

At BPLP’s option, loans under the 2021 Credit Facility will bear interest at a rate per annum equal to (1) (a) in the case of loans denominated in Dollars, LIBOR, (b) in the case of loans denominated in Euro, EURIBOR, (c) in the case of loans denominated in Canadian Dollars, CDOR, and (d) in the case of loans denominated in Sterling, SONIA, in each case, plus a margin ranging from 70.0 to 140.0 basis points based on BPLP’s credit rating or (2) an alternate base rate equal to the greatest of (a) the Federal Funds rate plus 0.5%, (b) the Administrative Agent’s prime rate, (c) LIBOR for a one-month period plus 1.00%, and (d) 1.00%, in each case, plus a margin ranging from 0 to 40 basis points based on BPLP’s credit rating. The 2021 Credit Facility includes provisions which allow LIBOR Daily Floating Rate to be switched to SOFR.

The 2021 Credit Facility also features a sustainability-linked pricing component such that if BPLP meets certain sustainability performance targets, the applicable per annum interest rate will be reduced by one basis point. The LIBOR replacement provisions in the 2021 Credit Facility permit the use of rates based on the secured overnight financing rate administered by the Federal Reserve Bank of New York plus an applicable spread adjustment. In addition, the 2021 Credit Facility contains a competitive bid option for up to 65% of the Revolving Facility that allows banks that are part of the lender consortium to bid to make loan advances to BPLP at a reduced interest rate.

Pursuant to the 2021 Credit Facility, BPLP is obligated to pay (1) in quarterly installments a facility fee on the total commitment under the Revolving Facility at a rate per annum ranging from 0.10% to 0.30% based on BPLP’s credit rating and (2) an annual fee on the undrawn amount of each letter of credit ranging from 0.70% to 1.40% based on BPLP’s credit rating.

Based on BPLP’s December 31, 2022 credit rating, (1) the applicable Eurocurrency and LIBOR Daily Floating Rate margins are 0.775%, (2) the alternate base rate margin is zero basis points and (3) the facility fee is 0.15% per annum.

At December 31, 2022, BPLP had no amount outstanding under its Revolving Facility. At December 31, 2021, BPLP had $145.0 million outstanding under its Revolving Facility.

Unsecured Term Loan

On May 17, 2022, BPLP entered into the 2022 Unsecured Term Loan, which provided for a single borrowing of up to $730.0 million. The 2022 Unsecured Term Loan matures on May 16, 2023 (See Note 16).

At BPLP’s option, the 2022 Unsecured Term Loan bore interest at a rate per annum equal to (A) (1) a base rate per annum equal to the greater of (a) the federal funds rate plus 0.5%, (b) the administrative agent’s prime rate, (c) term SOFR plus 1.00% and (d) 1.00%, or (2) a term SOFR rate per annum equal to the forward-looking SOFR term rate administered by CME Group Benchmark Administration (“CME”) two business days prior to the commencement of such interest period; or if the rate was unavailable, then the forward-looking SOFR term rate administered by CME on the first business day immediately prior thereto, in each case, plus 0.10%, and (B) a margin ranging from zero to 160 basis points based on BPLP’s credit rating.

On May 17, 2022, BPLP exercised its option to draw $730.0 million under the 2022 Unsecured Term Loan (See Note 3). As of December 31, 2022, the 2022 Unsecured Term Loan bore interest at a variable rate equal to term SOFR plus 0.95% per annum based on BPLP’s credit rating at December 31, 2022. At December 31, 2022, BPLP had $730.0 million outstanding under the 2022 Unsecured Term Loan (see Note 16).

2021 Credit Facility and 2022 Unsecured Term Loan Compliance

The 2021 Credit Facility and 2022 Unsecured Term Loan contain customary representations and warranties, affirmative and negative covenants and events of default provisions, including the failure to pay indebtedness, breaches of covenants and bankruptcy and other insolvency events, which could result in the acceleration of the obligation to repay, in the case of the 2021 Credit Facility, all outstanding amounts and the cancellation of all commitments outstanding under the 2021 Credit Facility and, in the case of the 2022 Unsecured Term Loan, any outstanding amount under the 2022 Unsecured Term Loan. Among other covenants, the 2021 Credit Facility and the 2022 Unsecured Term Loan require that BPLP maintain on an ongoing basis: (1) a leverage ratio not to exceed 60%, however, the leverage ratio may increase to no greater than 65% provided that it is reduced back to 60% within one year, (2) a secured debt leverage ratio not to exceed 55%, (3) a fixed charge coverage ratio of at least 1.40, (4) an unsecured debt leverage ratio not to exceed 60%, however, the unsecured debt leverage ratio may increase to no greater than 65% provided that it is reduced to 60% within one year, (5) an unsecured debt interest coverage ratio of at least 1.75 and (6) limitations on permitted investments. At December 31, 2022, BPLP was in compliance with each of these financial and other covenant requirements.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 470
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
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-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

+ Details

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	16. Subsequent Events On January 4, 2023, BPLP entered into the 2023 Unsecured Term Loan, which provided for a single borrowing of up to $1.2 billion. Under the credit agreement, BPLP may, at any time prior to the maturity date, increase total commitments by up to an additional $300.0 million in aggregate principal amount by increasing the existing 2023 Unsecured Term Loan or incurring one or more additional term loans, in each case, subject to syndication of the increase and other conditions. The 2023 Unsecured Term Loan matures on May 16, 2024, with one 12-month extension option, subject to customary conditions. Upon entry into the credit agreement, BPLP exercised its option to draw $1.2 billion under the 2023 Unsecured Term Loan, a portion of which was used to repay in full the 2022 Unsecured Term Loan, which was scheduled to mature on May 16, 2023 (see Note 7). At BPLP’s option, loans under the 2023 Unsecured Term Loan will bear interest at a rate per annum equal to (1) a base rate equal to the greatest of (a) the Federal Funds rate plus 1/2 of 1%, (b) the administrative agent’s prime rate, (c) Term SOFR for a one-month period plus 1.00%, and (d) 1.00%, in each case, plus a margin ranging from 0 to 60 basis points based on BPLP’s credit rating; or (2) a rate equal to adjusted Term SOFR with a one-month period plus a margin ranging from 75 to 160 basis points based on BPLP’s credit rating. Based on BPLP’s credit rating upon entry into the credit agreement, the base rate margin is 0 basis points and the Term SOFR margin is 0.85%. The 2023 Unsecured Term Loan currently bears interest at a rate equal to adjusted Term SOFR plus 0.85%. On January 5, 2023, the Company commenced the development of 290 Binney Street, an approximately 566,000 net rentable square feet laboratory/life sciences project in Cambridge, Massachusetts. Concurrent with the commencement of this project, the Company began demolition of the existing Kendall Center Blue Parking Garage to support the development of this project. 290 Binney Street is 100% pre-leased to AstraZeneca (See Note 3). On January 30, 2023, the Company commenced the redevelopment of 300 Binney Street at Kendall Center in Cambridge, Massachusetts. 300 Binney Street consisted of an approximately 195,000 net rentable square foot premier workplace that is being redeveloped into approximately 240,000 net rentable square feet of laboratory/life sciences space. The project is 100% pre-leased to a life sciences organization. On January 31, 2023, the Company acquired a 50% interest in a joint venture that owns 13100 and 13150 Worldgate Drive located in Herndon, Virginia for a gross purchase price of approximately $17.0 million. The acquisition was completed with available cash. 13100 and 13150 Worldgate Drive consists of two vacant office buildings aggregating approximately 350,000 rentable square feet and a 1,200-space structured parking deck situated on a 10-acre site. The joint venture intends to redevelop the property for residential use. There can be no assurance that the joint venture will commence the development on the terms currently contemplated or at all. On January 25, 2023, BXP’s Compensation Committee approved the 2023 Multi-Year Long-Term Incentive Program (the “2023 MYLTIP”) awards under the 2021 Plan to certain executive officers of BXP. Earned awards will range from zero to a maximum of 322,053 LTIP Units depending on BXP’s relative and absolute TSR performance, with a target of approximately 161,026 LTIP Units. Under ASC 718, the 2023 MYLTIP awards have an aggregate value of approximately $13.1 million. On February 3, 2023 and February 7, 2023, BXP issued an aggregate of 64,731 shares of restricted common stock and BPLP issued an aggregate of 401,543 LTIP Units under the 2021 Plan to certain employees of BXP. On February 3, 2023, the measurement period for the Company’s 2020 MYLTIP awards ended and, based on BXP.’s relative TSR performance, the final payout was determined to be 50% of target, or an aggregate of approximately $3.8 million (after giving effect to employee separations). As a result, an aggregate of 152,460 2020 MYLTIP Units that had been previously granted were automatically forfeited.

Investments in Unconsolidated Joint Ventures

12 Months Ended

Dec. 31, 2022

Investments In Unconsolidated Joint Ventures [Abstract]

Investments In Unconsolidated Joint Ventures

6. Investments in Unconsolidated Joint Ventures

The investments in unconsolidated joint ventures consist of the following at December 31, 2022 and December 31, 2021:


					Carrying Value of Investment (1)
Entity	Properties	Nominal % Ownership			December 31, 2022		December 31, 2021
					(in thousands)
Square 407 Limited Partnership	Market Square North	50.00	%		$	(6,198)	$	(1,205)
BP/CRF Metropolitan Square LLC	Metropolitan Square	20.00	%		(37,629)		(15,356)
901 New York, LLC	901 New York Avenue	25.00	%	(2)	(12,493)		(12,597)
WP Project Developer LLC	Wisconsin Place Land and Infrastructure	33.33	%	(3)	31,971		33,732
500 North Capitol Venture LLC	500 North Capitol Street, NW	30.00	%		(9,185)		(7,913)
501 K Street LLC	1001 6th Street	50.00	%	(4)	42,922		42,576
Podium Developer LLC	The Hub on Causeway - Podium	50.00	%		46,839		48,980
Residential Tower Developer LLC	Hub50House	50.00	%		45,414		47,774
Hotel Tower Developer LLC	The Hub on Causeway - Hotel Air Rights	50.00	%		12,366		11,505
Office Tower Developer LLC	100 Causeway Street	50.00	%		59,716		57,687
1265 Main Office JV LLC	1265 Main Street	50.00	%		3,465		3,541
BNY Tower Holdings LLC	Dock 72	50.00	%	(5)	(19,921)		28,412

CA-Colorado Center, LLC	Colorado Center	50.00	%		233,862		231,479
7750 Wisconsin Avenue LLC	7750 Wisconsin Avenue	50.00	%		52,152		61,626
BP-M 3HB Venture LLC	3 Hudson Boulevard	25.00	%		116,397		116,306
SMBP Venture LP	Santa Monica Business Park	55.00	%		164,735		156,639
Platform 16 Holdings LP	Platform 16	55.00	%	(6)	158,109		109,086
Gateway Portfolio Holdings LLC	Gateway Commons	50.00	%	(7)	324,038		327,148
Rosecrans-Sepulveda Partners 4, LLC	Beach Cities Media Campus	50.00	%		27,000		27,106
Safeco Plaza REIT LLC	Safeco Plaza	33.67	%	(8)	69,785		72,545
360 PAS Holdco LLC	360 Park Avenue South	42.21	%	(9)	114,992		106,855
PR II/BXP Reston Gateway LLC	Reston Next Residential	20.00	%	(10)	11,351		N/A
751 Gateway Holdings LLC	751 Gateway	49.00	%	(7)	80,714		N/A
200 Fifth Avenue JV LLC	200 Fifth Avenue	26.69	%		120,083		N/A
					$	1,630,485	$	1,445,926

_______________

(1)Investments with deficit balances aggregating approximately $85.4 million and $37.1 million at December 31, 2022 and December 31, 2021, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.

(2)The Company’s economic ownership has increased based on the achievement of certain return thresholds. At December 31, 2022 and December 31, 2021, the Company’s economic ownership was approximately 50%.

(3)The Company’s wholly-owned subsidiary that owns Wisconsin Place Office also owns a 33.33% interest in the joint venture entity that owns the land, parking garage and infrastructure of the project.

(4)Under the joint venture agreement for this land parcel, the partner will be entitled to up to two additional payments from the venture based on increases in total entitled square footage of the project in excess of 520,000 square feet and achieving certain project returns at stabilization.

(5)This property includes net equity balances from the amenity joint venture.

(6)This entity is a VIE (See Note 2).

(7)On June 16, 2022, in accordance with the Gateway Commons joint venture agreement, 751 Gateway was segregated into a new single-purpose joint venture.

(8)The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture.

(9)The Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 5.837% indirect ownership in the joint venture, and (3) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture. The Company’s partners will fund required capital until their aggregate investment is

approximately 58% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.

(10)The Company’s partner will fund required capital until its aggregate investment is approximately 80% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.

Certain of the Company’s unconsolidated joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of its interest in the joint ventures. Under certain of the Company’s joint venture agreements, if certain return thresholds are achieved, the partners or the Company will be entitled to an additional promoted interest or payments.

The combined summarized balance sheets of the Company’s unconsolidated joint ventures are as follows:


	December 31, 2022		December 31, 2021
	(in thousands)
ASSETS
Real estate and development in process, net (1)	$	6,537,554	$	5,579,218
Other assets	756,786		586,470
Total assets	$	7,294,340	$	6,165,688
LIABILITIES AND MEMBERS’/PARTNERS’ EQUITY
Mortgage and notes payable, net	$	4,022,746	$	3,214,961
Other liabilities (2)	716,271		652,135
Members’/Partners’ equity	2,555,323		2,298,592
Total liabilities and members’/partners’ equity	$	7,294,340	$	6,165,688
Company’s share of equity	$	1,238,929	$	1,104,175
Basis differentials (3)	391,556		341,751
Carrying value of the Company’s investments in unconsolidated joint ventures (4)	$	1,630,485	$	1,445,926

_______________

(1)At December 31, 2022 and December 31, 2021, this amount included right of use assets - finance leases totaling approximately $248.9 million. At December 31, 2022 and December 31, 2021, this amount included right of use assets - operating leases totaling approximately $21.2 million and $22.3 million, respectively.

(2)At December 31, 2022 and December 31, 2021, this amount included lease liabilities - finance leases totaling approximately $382.2 million and $385.5 million, respectively. At December 31, 2022 and December 31, 2021, this amount included lease liabilities - operating leases totaling approximately $30.5 million and $30.4 million, respectively.

(3)This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The majority of the Company’s basis differences are as follows:


	December 31, 2022		December 31, 2021
Property	(in thousands)
Colorado Center	$	301,820	$	304,776
200 Fifth Avenue	94,497		N/A
Gateway Commons	47,808		51,009
Dock 72	(98,980)		(50,051)

These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

(4)Investments with deficit balances aggregating approximately $85.4 million and $37.1 million at December 31, 2022 and December 31, 2021, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets.

The combined summarized statements of operations of the Company’s unconsolidated joint ventures are as follows:


	Year ended December 31,
		2022		2021		2020
		(in thousands)
Total revenue (1)		$	512,078	$	383,649	$	319,560
Expenses
Operating		198,632		158,498		144,347
Transaction costs		837		470		1,027
Depreciation and amortization		181,041		147,121		141,853
Total expenses		380,510		306,089		287,227
Other income (expense)
Loss from early extinguishment of debt		(1,327)		—		—
Interest expense		(154,065)		(108,884)		(98,051)
Unrealized gain on derivative instruments		1,681		—		—
Gains on sales of real estate (2)		—		—		11,737
Net loss		$	(22,143)	$	(31,324)	$	(53,981)

Company’s share of net loss		$	(2,551)	$	(10,254)	$	(16,256)
Gain on sale of investment (3)		—		10,257		—
Impairment loss on investment (4)		(50,705)		—		(60,524)
Basis differential (5)		(6,584)		(2,573)		(8,330)
Loss from unconsolidated joint ventures		$	(59,840)	$	(2,570)	$	(85,110)

_______________

(1)Includes straight-line rent adjustments of approximately $62.9 million, $17.2 million and $(10.1) million for the years ended December 31, 2022, 2021 and 2020, respectively.

(2)For the year ended December 31, 2020, represents the gain on sale of Annapolis Junction Building Eight and two land parcels. The gain on sale of real estate is included in Loss from Unconsolidated Joint Ventures in the Company’s Consolidated Statements of Operations.

(3)During the year ended December 31, 2021, the Company completed the sale of its 50% ownership interest in Annapolis Junction NFM LLC. The Company recognized a gain on sale of investment of approximately $10.3 million.

(4)During the years ended December 31, 2022 and December 31, 2020, the Company recognized an other-than-temporary impairment loss on its investment in the unconsolidated joint venture that owns Dock 72 in Brooklyn, New York totaling approximately $50.7 million and $60.5 million, respectively.

(5)Includes straight-line rent adjustments of approximately $0.5 million, $0.8 million and $1.8 million for the years ended December 31, 2022, 2021 and 2020, respectively. Also includes net above-/below-market rent adjustments of approximately $0.4 million, $0.4 million and $0.9 million for the years ended December 31, 2022, 2021 and 2020, respectively.

On January 18, 2022, a joint venture in which the Company owns a 50% interest commenced the redevelopment of 651 Gateway located in South San Francisco, California. 651 Gateway is a premier workplace that is being converted to approximately 327,000 net rentable square feet of life sciences space.

On February 2, 2022, a joint venture in which the Company owns a 55% interest commenced the development of the first phase of Platform 16, a premier workplace project located in San Jose, California, that is expected to contain approximately 1.1 million net rentable square feet upon completion. The first phase of the development projects includes the construction of an approximately 390,000 net rentable square foot premier workplace building and a below-grade parking garage.

On March 28, 2022, a joint venture in which the Company owns a 20% interest refinanced with a new lender the debt secured by its Metropolitan Square property located in Washington, DC. At the time of the refinancing, the loan had an outstanding balance of approximately $294.1 million, bore interest at a variable rate equal to (1) the greater of (x) LIBOR or (y) 0.65%, plus (2) 4.75% per annum and was scheduled to mature on July 7, 2022, with two, one-year extension options, subject to certain conditions. There was no prepayment penalty associated with

the prepayment of the previous mortgage loan. The joint venture recognized a loss from early extinguishment of debt totaling approximately $1.3 million due to the write-off of unamortized deferred financing costs. In conjunction with the refinancing, the joint venture settled its interest rate cap agreement, entered into in 2020, to limit its exposure to increases in the LIBOR rate. The new mortgage and mezzanine loans have an aggregate principal balance of $420.0 million, bear interest at a weighted average variable rate equal to the Secured Overnight Financing Rate (“SOFR“) plus 2.75% per annum and mature on April 9, 2024, with three, one-year extension options, subject to certain conditions. The joint venture distributed excess loan proceeds from the new mortgage and mezzanine loans totaling approximately $100.5 million, of which the Company’s share totaled approximately $20.1 million. On September 1, 2022, the joint venture entered into an interest rate cap agreement that capped SOFR at 4.50% per annum on a notional amount of $420.0 million through April 15, 2024. Metropolitan Square is a premier workplace with approximately 657,000 net rentable square feet located in Washington, DC.

On April 18, 2022, a joint venture in which the Company owns a 50% interest extended the maturity date of the construction loan collateralized by its Hub50House property to June 19, 2022. At the time of the extension, the loan had an outstanding balance of approximately $176.5 million, bore interest at a variable rate equal to LIBOR plus 2.00% per annum and was scheduled to mature on April 19, 2022. On June 17, 2022, the joint venture repaid the existing construction loan and obtained a new mortgage loan. The new mortgage loan has a principal balance of $185.0 million, bears interest at a variable rate equal to SOFR plus 1.35% per annum and matures on June 17, 2032. At closing, the joint venture entered into interest rate swap contracts with notional amounts aggregating $185.0 million through April 10, 2032, resulting in a fixed rate of approximately 4.432% per annum through the expiration of the interest rate swap contracts. In conjunction with the new mortgage loan, the joint venture paid off the existing construction loan. At the time of the payoff of the construction loan, the outstanding balance of the loan totaled approximately $176.7 million. The joint venture distributed excess loan proceeds from the new mortgage loan totaling approximately $6.8 million, of which the Company’s share totaled approximately $3.4 million. Hub50House is a residential property that consists of approximately 320,000 net rentable square feet and 440 residential units located in Boston, Massachusetts.

On May 13, 2022, the Company entered into a joint venture with a third party to own, operate and develop Reston Next Residential located in Reston, Virginia. Reston Next Residential is expected to consist of 508 residential rental units upon completion. The Company contributed approximately $11.3 million of improvements at closing and will contribute cash totaling approximately $3.5 million post closing for its 20% ownership interest in the joint venture. The partner contributed approximately $0.5 million of cash at closing and will contribute cash totaling approximately $58.7 million in the future for its 80% ownership interest in the joint venture. As a result of the partner’s deferred contribution, as of the acquisition date, the Company owned an approximately 96% interest in the joint venture. On May 13, 2022, the joint venture commenced development and entered into a construction loan collateralized by the property. The construction loan has a principal amount of up to $140.0 million, bears interest at a variable rate equal to SOFR plus 2.00% per annum and matures on May 13, 2026, with two, one-year extension options, subject to certain conditions.

On June 16, 2022, the Company entered into a joint venture with a third party to own, operate and develop 751 Gateway, a laboratory building located in South San Francisco, California, that is expected to be approximately 231,000 net rentable square feet upon completion. 751 Gateway was previously part of the Company’s Gateway Commons joint venture. The Company contributed assets with an agreed upon value aggregating approximately $53.9 million and cash totaling approximately $2.6 million for its 49% ownership interest in the joint venture. The partner contributed assets with an agreed upon value aggregating approximately $53.9 million and cash totaling approximately $4.9 million for its 51% ownership interest in the joint venture.

On August 8, 2022, a joint venture in which the Company owns a 50% interest modified the construction loan collateralized by its Dock 72 property located in Brooklyn, New York. At the time of the modification, the loan had an outstanding balance totaling approximately $198.4 million, a total commitment amount of $250.0 million, bore interest at a variable rate equal to LIBOR plus 3.35% per annum, and was scheduled to mature on December 18, 2023. The modified construction loan bore interest at a variable rate equal to (1) the greater of (x) SOFR or (y) 0.25% plus (2) 3.10% per annum, has a total commitment amount of approximately $198.4 million, and continued to mature on December 18, 2023. On December 22, 2022, the joint venture further modified the construction loan. The further modified construction loan bears interest at a variable rate equal to (1) the greater of (x) SOFR or (y) 0.25% plus (2) 2.50% per annum, has a total commitment amount of approximately $198.4 million, and matures on December 18, 2025. During December 2022, the Company recognized a non-cash impairment charge totaling approximately $50.7 million, which represented the other-than temporary decline in the fair value below the carrying value of the Company’s investment in the unconsolidated joint venture that owns Dock 72. The Company assessed the impairment and concluded that it was other than temporary. The Company determined that its valuation of the

investment was categorized within Level 3 of the fair value hierarchy, as it utilized significant unobservable inputs in its assessment including an exit capitalization rate of 5.75%, a discount rate on the Company’s equity investment (the property is encumbered by mortgage debt) of 7.0% and leasing the currently available space over the period of 2023-2026. Dock 72 is a premier workplace with approximately 669,000 net rentable square feet.

On September 9, 2022, a joint venture in which the Company owns an approximate 33.67% interest modified the mortgage loan collateralized by its Safeco Plaza property located in Seattle, Washington. At the time of the modification, the loan had an outstanding balance of approximately $250.0 million, bore interest at a variable rate equal to the greater of (x) 2.35% or (y) LIBOR plus 2.20% per annum, and was scheduled to mature on September 1, 2026. The modified mortgage loan bears interest at a variable rate equal to the greater of (x) 2.35% or (y) SOFR plus 2.32% per annum and continues to mature on September 1, 2026. In conjunction with the loan modification, the joint venture entered into an interest rate cap agreement that capped SOFR at 2.50% per annum on a notional amount of $250.0 million through September 1, 2023. Safeco Plaza is a premier workplace with approximately 765,000 net rentable square feet.

On November 17, 2022, the Company acquired a 26.69% interest in the joint venture that owns 200 Fifth Avenue located in New York, New York, for a gross purchase price of approximately $280.2 million, which included $120.1 million of cash and the Company’s pro rata share of the outstanding loan secured by the property of $160.1 million. The mortgage loan bears interest at a variable rate equal to LIBOR plus 1.30% per annum and matures on November 24, 2028. The joint venture has interest rate swap contracts with notional amounts aggregating $600.0 million through June 2028, resulting in a fixed rate of approximately 4.34% per annum through the expiration of the interest rate swap contracts. 200 Fifth Avenue is a 14-story, approximately 855,000 square-foot, LEED Gold certified, premier workplace located in the Midtown South submarket.

On December 7, 2022, a joint venture in which the Company owns a 50% interest modified the mortgage loan collateralized by its Market Square North property located in Washington, DC. At the time of the modification the loan had an outstanding balance of approximately $125.0 million, bore interest at a variable rate equal to (1) the greater of (x) LIBOR or (y) 0.50%, plus (2) 2.30% per annum, and was scheduled to mature on November 10, 2025, with one, one-year extension option subject to certain conditions. The modified mortgage loan bears interest at a variable rate equal to the greater of (1) the sum of (x) the “benchmark rate”, (y) 2.30% and (z) the adjustment applicable to such “benchmark rate” (approximately 0.11% for Term SOFR), or (2) 2.80%. For the period December 7, 2022 through March 9, 2023, the “benchmark rate” means LIBOR, and for the period after March 10, 2023, through the maturity date, Term SOFR. The modified mortgage loan continues to mature on November 10, 2025, with a one-year extension option subject to certain conditions. Market Square North is a premier workplace with approximately 418,000 net rentable square feet located in Washington, DC.

On December 23, 2022, a joint venture in which the Company owns a 50% interest modified the construction loan collateralized by its The Hub on Causeway – Podium property located in Boston, Massachusetts. At the time of the modification, the loan had an outstanding balance of approximately $174.3 million, bore interest at a variable rate equal to LIBOR plus 2.25% per annum, and was scheduled to mature on September 6, 2023. The modified construction loan continues to bear interest at a variable rate equal to LIBOR plus 2.25% per annum for the period from December 23, 2022 through April 30, 2023. For the period from May 1, 2023 through the maturity date, the construction loan bears interest at a variable rate equal to Term SOFR plus 2.35% per annum. The modified construction loan continues to mature on September 6, 2023. The Hub on Causeway – Podium is a premier workplace with approximately 380,000 net rentable square feet located in Boston, Massachusetts.

On December 23, 2022, a joint venture in which the Company owns a 50% interest modified the construction loan collateralized by its 100 Causeway Street property located in Boston, Massachusetts. At the time of the modification, the loan had an outstanding balance of approximately $337.6 million, bore interest at a variable rate equal to LIBOR plus 1.50% per annum, and was scheduled to mature on September 5, 2023, with two, one-year extension options, subject to certain conditions. The modified construction loan continues to bear interest at a variable rate equal to LIBOR plus 1.50% per annum for the period from December 23, 2022 through April 30, 2023. For the period from May 1, 2023 through the maturity date, the construction loan will bear interest at a variable rate equal to Term SOFR plus 1.60% per annum. The modified construction loan continues to mature on September 5, 2023, with two, one-year extension options, subject to certain conditions. 100 Causeway Street is a premier workplace with approximately 630,000 net rentable square feet located in Boston, Massachusetts.

Summary Of Significant Accounting Policies

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Summary Of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Real Estate

Upon acquisitions of real estate, the Company assesses whether the transaction should be accounted for as an asset acquisition or as a business combination by applying a screen to determine whether the integrated set of assets and activities acquired meets the definition of a business. Acquisitions of integrated sets of assets and activities that do not meet the definition of a business are accounted for as asset acquisitions. The Company’s acquisitions of real estate or in-substance real estate generally will not meet the definition of a business because substantially all of the fair value is concentrated in a single identifiable asset or group of similar identifiable assets (i.e. land, buildings, and related intangible assets) or because the acquisition does not include a substantive process in the form of an acquired workforce or an acquired contract that cannot be replaced without significant cost, effort or delay.

The Company assesses the fair value of acquired tangible and intangible assets (including land, buildings, tenant improvements, “above-” and “below-market” leases, leasing and assumed financing origination costs, acquired in-place leases, other identified intangible assets and assumed liabilities) and allocates the purchase price to the acquired assets and assumed liabilities, including land and buildings as if vacant. The Company assesses fair value based on estimated cash flow projections that utilize discount and/or capitalization rates that it deems appropriate, as well as available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known and anticipated trends, and market and economic conditions.

The fair value of the tangible assets of an acquired property considers the value of the property as if it were vacant. The Company also considers an allocation of purchase price of other acquired intangibles, including acquired in-place leases that may have a customer relationship intangible value, including (but not limited to) the nature and extent of the existing relationship with the tenants, the tenants’ credit quality and expectations of lease renewals. Based on its acquisitions to date, the Company’s allocation to customer relationship intangible assets has been immaterial.

The Company records acquired “above-” and “below-market” leases at their fair values (using a discount rate which reflects the risks associated with the leases acquired) equal to the difference between (1) the contractual amounts to be paid pursuant to each in-place lease and (2) management’s estimate of fair market lease rates for each corresponding in-place lease, measured over a period equal to the remaining term of the lease for above-market leases and the initial term plus the term of any below-market fixed rate renewal options for below-market leases. Acquired “above-” and “below-market” lease values have been reflected within Prepaid Expenses and Other Assets and Other Liabilities, respectively, in the Company’s Consolidated Balance Sheets. Other intangible assets acquired include amounts for in-place lease values that are based on the Company’s evaluation of the specific characteristics of each tenant’s lease. Factors to be considered include estimates of carrying costs during hypothetical expected lease-up periods considering current market conditions, and costs to execute similar leases. In estimating carrying costs, the Company includes real estate taxes, insurance and other operating expenses and estimates of lost rentals at market rates during the expected lease-up periods, depending on local market conditions. In estimating costs to execute similar leases, the Company considers leasing commissions, legal and other related expenses.

Management reviews its long-lived assets for indicators of impairment following the end of each quarter and when events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. This evaluation of long-lived assets is dependent on a number of factors, including when there is an event or adverse change in the operating performance of the long-lived asset or a current expectation that, more likely than not, a long-lived asset will be sold or otherwise disposed of significantly before the end of its previously estimated useful life or hold period. An impairment loss is recognized if the carrying amount of an asset is not recoverable and exceeds its fair value. The evaluation of anticipated cash flows is subjective and is based in part on assumptions regarding anticipated hold periods, future occupancy, future rental rates, future capital requirements, discount rates and capitalization rates that could differ materially from actual results in future periods. Because cash flows on properties considered to be “long-lived assets to be held and used” are considered on an undiscounted basis to determine whether an asset may be impaired, the Company’s established strategy of holding properties over the long term directly decreases the likelihood of recording an impairment loss. If the Company’s hold strategy changes or market conditions otherwise dictate an earlier sale date, an impairment loss may be recognized, and such loss could be material. If the Company determines that an impairment has occurred, the affected assets must be reduced to their fair value.

Guidance in Accounting Standards Codification (“ASC”) 360 “Property Plant and Equipment” requires that qualifying assets and liabilities and the results of operations that have been sold, or otherwise qualify as “held for sale,” be presented as discontinued operations in all periods presented if the property operations are expected to be eliminated and the Company will not have significant continuing involvement following the sale. Discontinued operations presentation applies only to disposals representing a strategic shift that has (or will have) a major effect on an entity’s operations and financial results (e.g., a disposal of a major geographical area, a major line of business, a major equity method investment or other major parts of an entity). The components of the property’s net income that are reflected as discontinued operations include the net gain (or loss) upon the disposition of the property held for sale, operating results, depreciation and interest expense (if the property is subject to a secured loan). The Company generally considers assets to be “held for sale” when the transaction has been approved by BXP’s Board of Directors, or a committee thereof, and there are no known significant contingencies relating to the sale, such that a sale of the property within one year is considered probable. Following the classification of a property as “held for sale,” no further depreciation is recorded on the assets, and the asset is written down to the lower of carrying value or fair market value, less cost to sell.

Real estate is stated at depreciated cost. A variety of costs are incurred in the acquisition, development and leasing of properties. The cost of buildings and improvements includes the purchase price of property, legal fees and other acquisition costs. The Company capitalizes acquisition costs that it incurs to effect an asset acquisition and expenses acquisition costs that it incurs to effect a business combination, including legal, due diligence and other closing related costs. Costs directly related to the development of properties are capitalized. Capitalized development costs include interest, internal wages, property taxes, insurance, and other project costs incurred during the period of development. After the determination is made to capitalize a cost, it is allocated to the specific

component of the project that benefited from the investment. Determination of when a development project commences and capitalization begins, and when a development project is substantially complete and held available for occupancy and capitalization must cease, involves a degree of judgment. The Company’s capitalization policy on development properties follows the guidance in ASC 835-20 “Capitalization of Interest” and ASC 970 “Real Estate-General.” The costs of land and buildings under development include specifically identifiable costs.

Capitalized costs include pre-construction costs necessary to the development of the property, development costs (including architectural, engineering and design costs), construction costs, interest costs, real estate taxes, salaries and related costs and other costs incurred during the period of development. The Company begins the capitalization of costs during the pre-construction period, which it defines as activities that are necessary for the development of the property. The Company considers a construction project as substantially complete and held available for occupancy upon the completion of tenant improvements, but no later than one year from cessation of major construction activity. The Company ceases capitalization on the portion (1) substantially completed, (2) occupied or held available for occupancy, and capitalizes only those costs associated with the portion under construction or (3) if activities necessary for the development of the property have been suspended. Interest costs capitalized for the years ended December 31, 2022, 2021 and 2020 were approximately $52.1 million, $53.1 million and $53.9 million, respectively. Salaries and related costs capitalized for the years ended December 31, 2022, 2021 and 2020 were approximately $16.1 million, $13.7 million and $12.9 million, respectively.

Expenditures for repairs and maintenance are charged to operations as incurred. Significant betterments are capitalized. When assets are sold or retired, their costs and related accumulated depreciation are removed from the accounts with the resulting gains or losses reflected in net income or loss for the period.

The Company computes depreciation and amortization on properties using the straight-line method based on estimated useful asset lives. The Company allocates the acquisition cost of real estate to its components and depreciates or amortizes these assets (or liabilities) over their useful lives. The amortization of acquired “above-” and “below-market” leases and acquired in-place leases is recorded as an adjustment to revenue and depreciation and amortization, respectively, in the Consolidated Statements of Operations.

Depreciation is computed on a straight-line basis over the estimated useful lives of the assets as follows:


Land improvements						25 to 40 years
Buildings and improvements						10 to 40 years
Tenant improvements						Shorter of useful life or terms of related lease
Furniture, fixtures, and equipment						3 to 7 years

Cash and Cash Equivalents

Cash and cash equivalents consist of cash on hand and investments with maturities of three months or less from the date of purchase. The majority of the Company’s cash and cash equivalents are held at major commercial banks which may at times exceed the Federal Deposit Insurance Corporation limit of $250,000.

Cash Held in Escrows

Escrows include amounts established pursuant to various agreements for security deposits, property taxes, insurance and other costs. Escrows also include cash held by qualified intermediaries for possible investments in like-kind exchanges in accordance with Section 1031 of the Internal Revenue Code, as amended (the “Code”), in connection with sales of the Company’s properties.

Investments in Securities

The Company accounts for investments in equity securities at fair value, with gains or losses resulting from changes in fair value recognized currently in earnings. The Company maintains deferred compensation plans that are designed to allow officers and non-employee directors of BXP to defer a portion of the officer’s current income or the non-employee director’s current compensation on a pre-tax basis and receive a tax-deferred return on these deferrals based on the performance of specific investments selected by the officer or non-employee director. The Company’s obligation under the plans is that of an unsecured promise to pay the deferred compensation to the plan participants in the future. At December 31, 2022 and 2021, the Company had maintained approximately $32.3 million and $43.6 million, respectively, in separate accounts, which are not restricted as to their use. The Company recognized gains (losses) of approximately $(6.5) million, $5.6 million and $5.3 million on its investments in the

accounts associated with the Company’s deferred compensation plans during the years ended December 31, 2022, 2021 and 2020, respectively.

Tenant and Other Receivables

Tenant and other accounts receivable, other than accrued rents receivable, are expected to be collected within one year.

Notes Receivable

The Company accounts for notes receivable at their unamortized cost, net of any unamortized deferred fees or costs, premiums or discounts and an allowance for loan losses. Loan fees and direct costs associated with loans originated by the Company are deferred and amortized over the term of the note as interest income.

Deferred Charges

Deferred charges include leasing costs and certain financing fees. Leasing costs include acquired intangible in-place lease values and direct and incremental fees and costs incurred in the successful negotiation of leases, including brokerage and other costs which have been deferred and are being amortized on a straight-line basis over the terms of the respective leases. Unamortized leasing costs are charged to expense upon the early termination of the lease. Fully amortized deferred leasing costs are removed from the books upon the expiration of the lease. Financing fees included in deferred charges consist of external fees and costs incurred to obtain the Company’s revolving facility and if applicable, unsecured term loan and construction financing arrangements where there are not sufficient amounts outstanding to report the fees net of the debt liability. Such financing costs have been deferred and are being amortized over the terms of the respective financing and included within interest expense. Unamortized financing costs are charged to expense upon the early repayment or significant modification of the financing. Fully amortized deferred financing costs are removed from the books upon the maturity of the debt.

External fees and costs incurred to obtain mortgage financings and unsecured senior notes have been deferred and are presented as direct deductions from the carrying amounts of the corresponding debt liability. Such financing costs are being amortized over the terms of the respective financing and included within interest expense. Unamortized financing costs are charged to expense upon the early repayment or significant modification of the financing.

Non-Real Estate Investments

The Company measures its investments in non-real estate investments, which are primarily environmentally focused investment funds, at the readily determinable fair value of the investment. Changes in the fair value of these non-real estate investments are included in unrealized gain (loss) on non-real estate investments on the Consolidated Statements of Operations. The Company’s investment in non-real estate investments is shown within Prepaid and Other Assets in the Consolidated Balance Sheet. The Company recognized a net unrealized loss of approximately $0.2 million for the year ended December 31, 2022 due to the observable changes in fair value. Prior to the year ended December 31, 2022, the Company had not invested in non-real estate investments.

Investments in Unconsolidated Joint Ventures

The Company consolidates VIEs in which it is considered to be the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or that the holders of the equity investment at risk do not have substantive participating rights. The primary beneficiary is defined by the entity having both of the following characteristics: (1) the power to direct the activities that, when taken together, most significantly impact the variable interest entity’s performance, and (2) the obligation to absorb losses and the right to receive the returns from the variable interest entity that could potentially be significant to the VIE. For ventures that are not VIEs, the Company consolidates entities for which it has significant decision making control over the ventures’ operations. The Company’s judgment with respect to its level of influence or control of an entity involves the consideration of various factors including the form of the Company’s ownership interest, its representation in the entity’s governance, the size of its investment (including loans), estimates of future cash flows, its ability to participate in policy making decisions and the rights of the other investors to participate in the decision making process and to replace the Company as manager and/or liquidate the venture, if applicable. The Company’s assessment of its influence or control over an entity affects the presentation of these investments in the Company’s consolidated financial statements. In addition to evaluating control rights,

the Company consolidates entities in which the outside partner has no substantive kick-out rights to remove the Company as the managing member.

Accounts of the consolidated entity are included in the accounts of the Company and the noncontrolling interest is reflected on the Consolidated Balance Sheets as a component of equity or in temporary equity between liabilities and equity. Investments in unconsolidated joint ventures are recorded initially at cost, and subsequently adjusted for equity in earnings and cash contributions and distributions. Any difference between the carrying amount of these investments on the balance sheet and the underlying equity in net assets is amortized as an adjustment to equity in earnings of unconsolidated joint ventures over the life of the related asset. Under the equity method of accounting, the net equity investment of the Company is reflected within the Consolidated Balance Sheets, and the Company’s share of net income or loss from the joint ventures is included within the Consolidated Statements of Operations. The joint venture agreements may designate different percentage allocations among investors for profits and losses; however, the Company’s recognition of joint venture income or loss generally follows the joint venture’s distribution priorities, which may change upon the achievement of certain investment return thresholds. The Company may account for cash distributions in excess of its investment in an unconsolidated joint venture as income when the Company is not the general partner in a limited partnership and when the Company has neither the requirement nor the intent to provide financial support to the joint venture. The Company classifies distributions received from equity method investees within its Consolidated Statements of Cash Flows using the nature of the distribution approach, which classifies the distributions received on the basis of the nature of the activity or activities of the investee that generated the distribution as either a return on investment (classified as cash inflows from operating activities) or a return of investment (classified as cash inflows from investing activities). The Company’s investments in unconsolidated joint ventures are reviewed for indicators of impairment on a quarterly basis and the Company records impairment charges when events or circumstances change indicating that a decline in the fair values below the carrying amounts has occurred and such decline is other-than-temporary. This evaluation of the investments in unconsolidated joint ventures is dependent on a number of factors, including the performance of each investment and market conditions. The Company will record an impairment charge if it determines that a decline in the fair value below the carrying amount of an investment in an unconsolidated joint venture is other-than-temporary. The fair value is calculated using discounted cash flows which is subjective and considers assumptions regarding future occupancy, future rental rates, future capital requirements, debt interest rates and availability, discount rates and capitalization rates that could differ materially from actual results in future periods.

To the extent that the Company contributed assets to a joint venture, the Company’s investment in the joint venture was recorded at the Company’s cost basis in the assets that were contributed to the joint venture. To the extent that the Company’s cost basis is different than the basis reflected at the joint venture level, the basis difference is amortized over the life of the related asset and included in the Company’s share of equity in net income of the joint venture. In accordance with the provisions of ASC 610-20 “Gains and Losses from the Derecognition of Nonfinancial Assets” (“ASC 610-20”), the Company will recognize a full gain on both the retained and sold portions of real estate contributed or sold to a joint venture by recognizing its new equity method investment interest at fair value.

The combined summarized financial information of the unconsolidated joint ventures is disclosed in Note 6.

Revenue Recognition

In general, the Company commences lease/rental revenue recognition when the tenant takes possession of the leased space and the leased space is substantially ready for its intended use. Contractual lease/rental revenue is reported on a straight-line basis over the terms of the respective leases. The impact of the straight-line rent adjustment increased revenue by approximately $108.0 million, $104.3 million and $104.9 million for the years ended December 31, 2022, 2021 and 2020, respectively, as the revenue recorded exceeded amounts billed. Accrued rental income, as reported on the Consolidated Balance Sheets, represents cumulative lease/rental income earned in excess of rent payments received pursuant to the terms of the individual lease agreements.

The Company must estimate the collectability of its accrued rent and accounts receivable balances related to lease revenue. When evaluating the collectability of tenants’ accrued rent and accounts receivable balances, management considers tenants’ creditworthiness, current economic trends and changes in tenants’ payment patterns, on a lease-by-lease basis. The Company writes-off the tenant’s receivable balance, including the accrued rent receivable, if the Company considers the balances no longer probable of collection. In addition, tenants in bankruptcy are analyzed and considerations are made in connection with the expected recovery of pre-petition and post-petition claims. If the Company deems the balances no longer probable of collection, the Company writes

them off and ceases recognizing lease income, including straight-line rent, unless cash is received (See Note 4). Following a write-off, if (1) the Company subsequently determines that it is probable it will collect substantially all the remaining lessee’s lease payments under the lease term and (2) the lease has not been modified since the write-off, the Company will then reinstate the accrued rent and accounts receivable write-offs, adjusting for the amount related to the period when the lease payments were considered not probable of collection. If the Company’s estimates of collectability differs from the cash received, then the timing and amount of the Company’s reported revenue could be impacted. The credit risk is mitigated by the high quality of the Company’s existing tenant base, reviews of prospective tenants’ risk profiles prior to lease execution and consistent monitoring of the Company’s portfolio to identify potential problem tenants.

The Company recognizes acquired in-place “above-” and “below-market” leases at their fair values as rental revenue over the original term of the respective leases. The impact of the acquired in-place “above-” and “below-market” leases increased revenue by approximately $9.1 million, $4.2 million and $6.5 million for the years ended December 31, 2022, 2021 and 2020, respectively. The following table summarizes the scheduled amortization of the Company’s acquired “above-” and “below-market” lease intangibles for each of the five succeeding years (in thousands).


	Acquired Above-Market Lease Intangibles		Acquired Below-Market Lease Intangibles
2023	$	1,306	$	13,439
2024	401		9,811
2025	389		9,768
2026	389		8,647
2027	389		5,477

Recoveries from tenants, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized as revenue in the period during which the expenses are incurred (See “Leases” ). The Company receives reimbursements of payroll and payroll related costs from unconsolidated joint venture entities and third party property owners in connection with management services contracts which the Company reflects on a gross basis instead of on a net basis as the Company has determined that it is the principal and not the agent under these arrangements in accordance with the guidance in ASC 606 “Revenue from Contracts with Customers” (“ASC 606”).

The Company’s parking revenue is derived primarily from monthly and transient daily parking. In addition, the Company has certain lease arrangements for parking accounted for under the guidance in ASC 842 “Leases” (“ASC 842”). The monthly and transient daily parking revenue falls within the scope of ASC 606 and is accounted for at the point in time when control of the goods or services transfers to the customer and the Company’s performance obligation is satisfied.

The Company’s hotel revenue is derived from room rentals and other sources such as charges to guests for telephone service, movie and vending commissions, meeting and banquet room revenue and laundry services. Hotel revenue is recognized as the hotel rooms are occupied and the services are rendered to the hotel customers.

The Company earns management and development fees. Development and management services revenue is earned from unconsolidated joint venture entities and third-party property owners. The Company determined that the performance obligations associated with its development services contracts are satisfied over time and that the Company would recognize its development services revenue under the output method evenly over time from the development commencement date through the substantial completion date of the development management services project due to the stand-ready nature of the contracts. Significant judgments impacting the amount and timing of revenue recognized from the Company’s development services contracts include estimates of total development project costs from which the fees are typically derived and estimates of the period of time until substantial completion of the development project, the period of time over which the development services are required to be performed. The Company recognizes development fees earned from unconsolidated joint venture projects equal to its cost plus profit to the extent of the third party partners’ ownership interest. Property management fees are recorded and earned based on a percentage of collected rents at the properties under management, and not on a straight-line basis, because such fees are contingent upon the collection of rents.

Gains on sales of real estate are recognized pursuant to the provisions included in ASC 610-20. Under ASC 610-20, the Company must first determine whether the transaction is a sale to a customer or non-customer. The

Company typically sells real estate on a selective basis and not within the ordinary course of its business and therefore expects that its sale transactions will not be contracts with customers. The Company next determines whether it has a controlling financial interest in the property after the sale, consistent with the consolidation model in ASC 810 “Consolidation” (“ASC 810”). If the Company determines that it does not have a controlling financial interest in the real estate, it evaluates whether a contract exists under ASC 606 and whether the buyer has obtained control of the asset that was sold. The Company recognizes a full gain on sale of real estate when the derecognition criteria under ASC 610-20 have been met.

Leases

Lessee

For leases in which the Company is the lessee (generally ground leases), in accordance with ASC 842 the Company recognizes a right-of-use asset and a lease liability. The Company made the policy election to not apply the requirements of ASC 842 to short-term leases. This policy election is made by class of underlying assets and as described below, the Company considers real estate to be a class of underlying assets, and will not be further delineating it into specific uses of the real estate asset as the risk profiles are similar in nature. The Company will recognize the lease payments it pays in net income on a straight-line basis over the lease term.

The lease liability is equal to the present value of the minimum lease payments in accordance with ASC 842. The Company will use its incremental borrowing rate (“IBR”) to determine the net present value of the minimum lease payments. In order to determine the IBR, the Company utilized a market-based approach to estimate the incremental borrowing rate for each individual lease. The approach required significant judgment. Therefore, the Company utilized different data sets to estimate base IBRs via an analysis of the following weighted-components:

•the interpolated rates from yields on outstanding U.S. Treasury issuances for up to 30 years and for years 31 and beyond, longer-term publicly traded educational institution debt issued by high credit quality educational institutions with maturity dates exceeding 31 years,

•observable mortgage rates spread over U.S. Treasury issuances, and

•unlevered property yields and discount rates.

The Company then applied adjustments to account for considerations related to term and interpolated the IBR.

Lessor

Operating Leases

The Company leases primarily premier workplaces, including office, life sciences, retail and residential space to tenants. These leases may contain extension and termination options that are predominately at the sole discretion of the tenant, provided certain conditions are satisfied. In a few instances, the leases also contain purchase options, which would be exercisable at fair market value. Also, certain of the Company’s leases include rental payments that are based on a percentage of the tenant sales in excess of contractual amounts.

Per ASC 842, lessors do not need to separate nonlease components from the associated lease component if certain criteria stated above are met for each class of underlying assets. The guidance in ASC 842 defines “underlying asset” as “an asset that is the subject of a lease for which a right to use that asset has been conveyed to a lessee. The underlying asset could be a physically distinct portion of a single asset.” Based on the above guidance, the Company considers real estate assets as a class of underlying assets and will not be further delineating it into specific uses of the real estate asset as the risk profiles are similar in nature.

Lease components are elements of an arrangement that provide the customer with the right to use an identified asset. Nonlease components are distinct elements of a contract that are not related to securing the use of the leased asset and revenue is recognized in accordance with ASC 606. The Company considers common area maintenance (CAM) and service income associated with tenant work orders to be nonlease components because they represent delivery of a separate service but are not considered a cost of securing the identified asset. In the case of the Company’s business, the identified asset would be the leased real estate (office, life sciences, retail or residential).

The Company assessed and concluded that the timing and pattern of transfer for nonlease components and the associated lease component are the same. The Company determined that the predominant component was the lease component and as such its leases will continue to qualify as operating leases and the Company has made a

policy election to account for and present the lease component and the nonlease component as a single component in the revenue section of the Consolidated Statements of Operations labeled Lease.

Recoveries from tenants, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized as revenue in the period during which the expenses are incurred. The Company recognizes these reimbursements on a gross basis, as the Company obtains control of the goods and services before they are transferred to the tenant.

In addition, in accordance with ASC 842, lessors will only capitalize incremental direct leasing costs.

Sales-Type Leases

Sales-type lease receivables are recognized when a lease qualifies as a sales-type lease. The sales-type lease receivable is initially measured at the present value of the fixed and determinable lease payments, including any guaranteed or unguaranteed residual value of the asset at the end of the lease, discounted at the rate implicit in the lease. The Company evaluates its sales-type lease receivable for impairment under the current expected credit loss standard. Interest income is recognized under the effective interest method. The effective interest method produces a constant yield on the sales-type lease receivable over the term of the lease. Income from these leases are classified as Lease Revenue within the Consolidated Statement of Operations.

Earnings Per Share

Basic earnings per share (“EPS”) is computed by dividing net income available to common shareholders, as adjusted for undistributed earnings (if any) of certain securities issued by BPLP, by the weighted average number of shares of Common Stock outstanding during the year. Diluted EPS reflects the potential dilution that could occur from shares issuable in connection with awards under stock-based compensation plans, including upon the exercise of stock options, and securities of BPLP that are exchangeable for Common Stock.

Earnings Per Common Unit

Basic earnings per common unit is computed by dividing net income available to common unitholders, as adjusted for undistributed earnings (if any) of certain securities issued by BPLP, by the weighted average number of common units outstanding during the year. Diluted earnings per common unit reflects the potential dilution that could occur from units issuable in connection with awards under BXP’s stock-based compensation plans, including upon the exercise of stock options, and conversion of preferred units of BPLP.

Recurring Fair Value of Financial Instruments

The Company follows the authoritative guidance for fair value measurements when valuing its financial instruments for disclosure purposes. The table below presents for December 31, 2022 and 2021, the financial instruments that are being valued for disclosure purposes as well as the Level at which they are categorized as defined in ASC 820 “Fair Value Measurements and Disclosures” (“ASC 820”).


Financial Instrument			Level
Unsecured senior notes (1)			Level 1
Related party note receivable			Level 3
Notes receivable			Level 3
Sales-type lease receivable			Level 3
Mortgage notes payable			Level 3
Unsecured line of credit			Level 3
Unsecured term loan			Level 3

_______________

(1)If trading volume for the period is low, the valuation could be categorized as Level 2.

Because the Company’s valuations of its financial instruments are based on the above Levels and involve the use of estimates, the actual fair values of its financial instruments may differ materially from those estimates.

In addition, the Company’s estimated fair values for these instruments as of the end of the applicable reporting period are not projections of, nor necessarily indicative of, estimated or actual fair values in future reporting periods.

The following table presents the aggregate carrying value of the Company’s related party note receivable, net, notes receivable, net, sales-type lease receivable, net, mortgage notes payable, net, unsecured senior notes, net, unsecured line of credit and unsecured term loan, net and the Company’s corresponding estimate of fair value as of December 31, 2022 and December 31, 2021 (in thousands):


	December 31, 2022				December 31, 2021
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Related party note receivable, net	$	78,576	$	79,220	$	78,336	$	82,867
Note receivable, net	—		—		9,641		10,000
Sales-type lease receivable, net	12,811		13,045		—		—
Total	$	91,387	$	92,265	$	87,977	$	92,867

Mortgage notes payable, net	$	3,272,368	$	2,744,479	$	3,267,914	$	3,395,569
Unsecured senior notes, net	10,237,968		9,135,512		9,483,695		9,966,591
Unsecured line of credit	—		—		145,000		145,317
Unsecured term loan, net	730,000		730,000		—		—
Total	$	14,240,336	$	12,609,991	$	12,896,609	$	13,507,477

The Company uses interest rate swap agreements to manage its interest rate risk. The valuation of these instruments is determined using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves. To comply with the provisions of ASC 820, the Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. Although the Company determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by the Company and its counterparties. The Company assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and determined that the credit valuation adjustments were not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy.

Derivative Instruments and Hedging Activities

Derivative instruments and hedging activities require management to make judgments on the nature of its derivatives and their effectiveness as hedges. These judgments determine if the changes in fair value of the derivative instruments are reported in the Consolidated Statements of Operations as a component of net income or as a component of comprehensive income and as a component of equity on the Consolidated Balance Sheets. While management believes its judgments are reasonable, a change in a derivative’s effectiveness as a hedge could materially affect expenses, net income and equity. The Company accounts for both the effective and ineffective portions of changes in the fair value of a derivative in other comprehensive income (loss) and subsequently reclassifies the fair value of the derivative to earnings over the term that the hedged transaction affects earnings and in the same line item as the hedged transaction within the statements of operations.

During the year ended December 31, 2020, the Company elected to apply hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. The Company’s application of this expedient preserves the presentation of derivatives consistent with past presentation.

Stock-Based Employee Compensation Plans

At December 31, 2022, the Company had a stock-based employee compensation plan. The Company accounts for the plan under the guidance in ASC 718 “Compensation – Stock Compensation” (“ASC 718”), which revised the fair value based method of accounting for share-based payment liabilities, forfeitures and modifications of stock-based awards and clarified previous guidance in several areas, including measuring fair value, classifying an award as equity or as a liability and attributing compensation cost to reporting periods.

Use of Estimates in the Preparation of Financial Statements

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. These estimates include such items as depreciation and allowances for doubtful accounts. Actual results could differ from those estimates.

The Company bases its estimates on historical experience and on various other assumptions that it considers to be reasonable under the circumstances, including the impact of extraordinary events such as COVID-19, the results of which form the basis for making significant judgments about the carrying values of assets and liabilities, assessments of future collectability, and other areas of the financial statements that are impacted by the use of estimates. Actual results may differ from these estimates under different assumptions or conditions.

BXP

Equity Offering Costs

Underwriting commissions and offering costs have been reflected as a reduction of additional paid-in capital.

Treasury Stock

BXP’s share repurchases are reflected as treasury stock utilizing the cost method of accounting and are presented as a reduction to consolidated stockholders’ equity.

Dividends

Earnings and profits, which determine the taxability of dividends to stockholders, will differ from income reported for financial reporting purposes due to the differences for federal income tax purposes in the treatment of gains/losses on the sale of real property, revenue and expense recognition, compensation expense, and in the estimated useful lives and basis used to compute depreciation.

The tax treatment of common dividends per share for federal income tax purposes is as follows:


	For the year ended December 31,
	2022					2021					2020
	Per Share			%		Per Share			%		Per Share			%
Ordinary income	$	3.42		86.60	%	$	2.90		73.86	%	$	2.52		64.91	%
Capital gain income	0.53			13.40	%	0.57			14.57	%	0.99			25.49	%
Return of capital	—			—	%	0.45			11.57	%	0.37			9.60	%
Total	$	3.95	(1)	100.00	%	$	3.92	(2)	100.00	%	$	3.88	(3)	100.00	%

_____________

(1)The fourth quarter 2022 regular quarterly dividend was $0.98 per common share, of which approximately $0.03 per common share was allocable to 2022 and approximately $0.95 per common share was allocable to 2023.

(2)The fourth quarter 2021 regular quarterly dividend was $0.98 per common share, all of which was allocable to 2022.

(3)The fourth quarter 2020 regular quarterly dividend was $0.98 per common share, all of which was allocable to 2021.

Income Taxes

BXP has elected to be treated as a REIT under Sections 856 through 860 of the Code, commencing with its taxable year ended December 31, 1997. As a result, it generally will not be subject to federal corporate income tax on its taxable income that is distributed to its stockholders. A REIT is subject to a number of organizational and operational requirements, including a requirement that it currently distribute at least 90% of its annual taxable income (with certain adjustments). BXP’s policy is to distribute at least 100% of its taxable income. Accordingly, the only provision for federal income taxes in the accompanying consolidated financial statements relates to BXP’s consolidated taxable REIT subsidiaries. BXP’s taxable REIT subsidiaries did not have significant tax provisions or deferred income tax items. BXP has no uncertain tax positions recognized as of December 31, 2022 and 2021. At December 31, 2022, BXP’s tax returns for the years 2019 forward remain subject to examination by the major tax jurisdictions under the statute of limitations.

The Company owns a hotel property that it leases to one of its taxable REIT subsidiaries and that is managed by Marriott International, Inc. The hotel taxable REIT subsidiary, a wholly owned subsidiary of BPLP, is the lessee pursuant to the lease for the hotel property. As lessor, BPLP is entitled to a percentage of gross receipts from the hotel property. Marriott International, Inc. continues to manage the hotel property under the Marriott name and under terms of a management agreement. The hotel taxable REIT subsidiary is subject to tax at the federal and state level and, accordingly, if applicable, BXP has recorded a tax provision in its Consolidated Statements of Operations for the years ended December 31, 2022, 2021 and 2020.

Certain entities included in BXP’s consolidated financial statements are subject to certain state and local taxes. These taxes are recorded as operating expenses in the accompanying consolidated financial statements.

BPLP

Income Taxes

The partners are required to report their respective share of BPLP’s taxable income or loss on their respective tax returns and are liable for any related taxes thereon. Accordingly, the only provision for federal income taxes in the accompanying consolidated financial statements relates to BPLP’s consolidated taxable REIT subsidiaries. BPLP’s taxable REIT subsidiaries did not have significant tax provisions or deferred income tax items. BPLP has no uncertain tax positions recognized as of December 31, 2022 and 2021. At December 31, 2022, BPLP’s tax returns for the years 2019 forward remain subject to examination by the major tax jurisdictions under the statute of limitations.

The Company owns a hotel property which is managed through a taxable REIT subsidiary. The hotel taxable REIT subsidiary, a wholly owned subsidiary of BPLP, is the lessee pursuant to the lease for the hotel property. As lessor, BPLP is entitled to a percentage of gross receipts from the hotel property. Marriott International, Inc. continues to manage the hotel property under the Marriott name and under terms of a management agreement. The hotel taxable REIT subsidiary is subject to tax at the federal and state level and, accordingly, BPLP has, if applicable, recorded a tax provision in its Consolidated Statements of Operations for the years ended December 31, 2022, 2021 and 2020.

Certain entities included in BPLP’s consolidated financial statements are subject to certain state and local taxes. These taxes are recorded as operating expenses in the accompanying consolidated financial statements.

Mortgage Notes Payable, Net (Details) $ in Thousands	12 Months Ended
Mortgage Notes Payable, Net (Details) $ in Thousands	Dec. 31, 2022 USD ($) Rate	Dec. 31, 2021 USD ($) Rate
Debt Instrument [Line Items]
Mortgage notes payable, net \| $	$ 3,272,368	$ 3,267,914
Debt Instrument, Collateral	each collateralized by one or more buildings and related land included in real estate assets	each collateralized by one or more buildings and related land included in real estate assets
Number Of Variable Mortgage Loans	0	0
Mortgages [Member]
Debt Instrument [Line Items]
Mortgage notes payable, net \| $	$ 3,272,368	$ 3,300,000
Fixed Rate Mortgage [Member]
Debt Instrument [Line Items]
Mortgage notes payable, net \| $	$ 3,300,000	$ 3,300,000
Debt, Weighted Average Interest Rate \| Rate	3.24%	3.24%
Fixed Rate Mortgage [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage \| Rate	2.79%	2.79%
Fixed Rate Mortgage [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage \| Rate	3.43%	3.43%

Related Party Transactions (Details) $ in Thousands	12 Months Ended
Related Party Transactions (Details) $ in Thousands	Dec. 31, 2022 USD ($) ft² nonemployeedirectors shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($)	Dec. 16, 2021 shares
Related Party Transaction [Line Items]
Related party note receivable, net	$ 78,576	$ 78,336
Interest and Other Income	$ 11,940	5,704	$ 5,953
Number Of Non Employee Directors Electing To Receive Deferred Stock Units \| nonemployeedirectors	7
Separate Unrestricted Cash For Deferred Compensation Plan.	$ 32,300	43,600
Liability for directors	$ 417,545	$ 320,775
Common stock, shares issued \| shares	156,836,767	156,623,749
Reedemable deferred stock units, units \| shares	97,853	83,073
Boston Properties Limited Partnership
Related Party Transaction [Line Items]
Related party note receivable, net	$ 78,576	$ 78,336
Interest and Other Income	11,940	5,704	5,953
Liability for directors	$ 417,545	$ 320,775
Reedemable deferred stock units, units \| shares	97,853	83,073
Three Hudson Boulevard [Member]
Related Party Transaction [Line Items]
Net Rentable Area (in sf) \| ft²	2,000,000
Ownership Percentage	25.00%
Related party note receivable, net	$ 80,000
Loans Receivable, Basis Spread on Variable Rate	3.50%
Interest and Other Income	$ 5,600	$ 3,600	2,700
Director Cessation Member [Member]
Related Party Transaction [Line Items]
Common stock, shares issued \| shares				498
Director
Related Party Transaction [Line Items]
Separate Unrestricted Cash For Deferred Compensation Plan.	600	900
Liability for directors	600	900
Immediate Family Member of Management or Principal Owner
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0	0	914
Real Estate Brokerage Firm
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 1,600	$ 1,900	$ 3,400

Leases

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Leases of Lessor Disclosure [Text Block]

4. Leases

The Company estimates the collectability of its accrued rent and accounts receivable balances related to lease revenue. When evaluating the collectability of these accrued rent and accounts receivable balances, management considers tenant creditworthiness, current economic trends and changes in tenants’ payment patterns, on a lease-by-lease basis. During the years ended December 31, 2021 and 2020, the Company wrote off approximately $1.3 million and $90.3 million, respectively, related to accrued rent, net balances and accounts receivable, net balances. The write-offs were for tenants, primarily in the retail and co-working sectors, that either terminated their leases or for which the Company determined their accrued rent and/or accounts receivable balances were no longer probable of collection.

In April 2020, the FASB staff issued a question and answer document (“Lease Modification Q & A”) related to the application of lease accounting guidance for lease concessions, in accordance with ASC 842, as a result of COVID-19. The Company did not utilize the guidance provided in the Lease Modification Q & A and instead elected to continue to account for the COVID-19 lease concessions on a lease-by-lease basis in accordance with the existing lease modification accounting framework.

During the year ended December 31, 2022, the Company determined it was probable of collecting

substantially all of certain clients’ accrued rent and account receivable balances and, therefore, ceased recognizing

revenue from such clients on a cash basis. As a result of returning these clients to accrual basis accounting, the

Company reinstated approximately $1.5 million of accrued rent balances during the year ended December 31, 2022.

Lessor

Operating Leases

The following table summarizes the components of lease revenue recognized during the years ended December 31, 2022, 2021 and 2020 included within the Company's Consolidated Statements of Operations (in thousands):


	Year ended December 31,
Lease Revenue	2022		2021		2020
Fixed contractual payments	$	2,426,007	$	2,319,362	$	2,211,915
Variable lease payments	492,361		433,652		434,346
	$	2,918,368	$	2,753,014	$	2,646,261

The future contractual lease payments to be received (excluding operating expense reimbursements and percentage rent) by the Company as of December 31, 2022, under non-cancelable operating leases which expire on various dates through 2049 (in thousands):


Years Ending December 31,
2023	$	2,338,610
2024	2,321,135
2025	2,279,700
2026	2,212,455
2027	2,094,014
Thereafter	13,020,102

No single tenant represented more than 10.0% of the Company’s total lease revenue for the years ended December 31, 2022, 2021 and 2020.

Sales-type Lease

On July 29, 2020, the Company entered into a 99-year ground lease with a third-party hotel developer for land at its Reston Next property located in Reston, Virginia, which will support the development of a 267-room, approximately 241,000 square foot hotel property. The lease commenced on October 21, 2020 and upon commencement, the Company performed classification testing. The ground lease was subject to termination rights and as of the lease commencement date, the Company was not reasonably certain that those termination rights would not be exercised. As such, the Company accounted for the ground lease as an operating lease. On December 19, 2022, the Company amended the ground lease which included the elimination of the termination rights. As a result, this lease was reclassified as a sales-type lease.

The Company recorded a sales-type lease receivable of approximately $13.0 million, which includes an unguaranteed residual asset of approximately $17,000. The sales-type lease receivable was measured as the present value of the fixed and determinable lease payments, including the unguaranteed residual value of the asset at the end of the lease, discounted at the rate implicit in the lease.

In addition, the Company recorded a gain on sales-type lease of approximately $10.1 million associated with the derecognition of the asset. The Company did not recognize any interest income during the year ended December 31, 2022.

The following table provides the future contractual payments to be received as of December 31, 2022 (in thousands):


	Sales-Type
2023	$	—
2024	31
2025	124
2026	372
2027	756
Thereafter	268,249
Total lease payments to be received	269,532
Less:
Interest portion	256,504
Sales-type lease receivable	13,028
Unguaranteed residual asset	17
Current expected credit loss adjustment	(234)
Sales-type lease receivable, net	$	12,811

Lessee, Operating Leases

Lessee

The Company has four non-cancelable ground lease obligations, as lessee, which were classified as operating leases, with various initial term expiration dates through 2114 for the years ended December 31, 2022, 2021 and 2020. The Company recognizes ground rent expense on a straight-line basis over the term of the respective ground lease agreements. As of December 31, 2022, none of the amounts disclosed below for these ground leases contain variable payments, extension options or residual value guarantees.

The Company has four finance lease obligations with various initial term expiration dates through 2094 for the years ended December 31, 2022, 2021 and 2020.

The following table provides lease cost information for the Company’s operating and finance leases for the years ended December 31, 2022, 2021 and 2020 (in thousands):


	Year ended December 31,
Lease costs	2022		2021		2020
Operating lease costs	$	12,700	$	13,151	$	13,948
Finance lease costs
Amortization of right of use asset (1)	$	697	$	547	$	56
Interest on lease liabilities (2)	$	3,236	$	2,471	$	583

_______________

(1)The finance leases relate to either land, buildings or assets that remain in development. For land leases classified as finance leases because of a purchase option that the Company views as an economic incentive, the Company follows its existing policy and does not depreciate land because it is assumed to have an indefinite life. For all other finance leases, the Company would amortize the right of use asset over the shorter of the useful life of the asset or the lease term. If the finance lease relates to a property under development, the amortization of the right of use asset may be eligible for capitalization. For assets under development, depreciation may commence once the asset is placed in-service and depreciation would be recognized in accordance with the Company’s policy.

(2)One, two and three of the finance leases relate to assets under development for all or a portion of the years ended December 31, 2022, December 31, 2021 and December 31, 2020, respectively, and as such, a portion of the interest amount was capitalized.

The following table provides other quantitative information for the Company’s operating and finance leases as of December 31, 2022 and December 31, 2021:


	December 31, 2022		December 31, 2021
Other information
Weighted-average remaining lease term (in years)
Operating leases	49		50
Finance leases	68		69
Weighted-average discount rate
Operating leases	5.7	%	5.7	%
Finance leases	6.2	%	6.2	%

The following table provides a maturity analysis for the Company’s lease liabilities related to its operating and finance leases as of December 31, 2022 (in thousands):


	Operating		Finance
2023	$	22,415	$	9,306
2024 (1)	22,274		49,343
2025	10,308		9,971
2026	10,100		10,166
2027	9,885		10,364
Thereafter	528,915		1,352,647
Total lease payments	603,897		1,441,797
Less:
Interest portion	399,211		1,192,462
Present value of lease payments	$	204,686	$	249,335

_______________

(1)Finance lease payments in 2024 include approximately $38.7 million related to a purchase option that the Company is reasonably certain it will exercise.

The following table provides a maturity analysis for the Company’s lease liabilities related to its operating and finance leases as of December 31, 2021 (in thousands):


	Operating		Finance
2022	$	19,623	$	8,762
2023	25,333		10,826
2024 (1)	10,085		48,605
2025	10,307		9,971
2026	10,100		10,166
Thereafter	538,801		1,363,011
Total lease payments	614,249		1,451,341
Less:
Interest portion	409,688		1,206,920
Present value of lease payments	$	204,561	$	244,421

_______________

(1)Finance lease payments in 2024 include approximately $38.7 million related to a purchase option that the Company is reasonably certain it will exercise.

Sales Type Lease Maturity Schedule (Details) - USD ($)	Dec. 31, 2022	Dec. 19, 2022	Dec. 31, 2021
Sales-Type and Direct Financing Leases, Lease Receivable, Payments to be Received, Fiscal Year Maturity [Abstract]
2023	$ 0
2024	31,000
2025	124,000
2026	372,000
2027	756,000
Thereafter	268,249,000
Total lease payments to be received	269,532,000
Interest portion	256,504,000
Sales-type lease receivable, net	13,028,000	$ 13,000,000
Sales-type Lease, Unguaranteed Residual Asset	17,000	$ 17,000
Sales-type Lease, Net Investment in Lease, Allowance for Credit Loss	(234,000)
Sales-type lease receivable, net	$ 12,811,000		$ 0

SEC Schedule, Article 12-28, Real Estate and Accumulated Depreciation

12 Months Ended

Dec. 31, 2022

SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]

SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Text Block]

Item 15. Exhibits and Financial Statement Schedules.

(a) Financial Statement Schedule


Boston Properties, Inc. Schedule 3—Real Estate and Accumulated Depreciation December 31, 2022 (dollars in thousands)
Property Name	Type	Location	Encumbrances		Original				Costs Capitalized Subsequent to Acquisition		Land and Improvements		Building and Improvements		Land Held for Development		Development and Construction in Progress		Total		Accumulated Depreciation		Year(s) Built/Renovated	Year(s) Acquired	Depreciable Lives (Years)

					Land		Building
767 Fifth Avenue (the General Motors Building)	Office	New York, NY	$	2,284,510	$	1,796,252	$	1,532,654	$	325,762	$	1,796,252	$	1,858,416	$	—	$	—	$	3,654,668	$	457,344	1968/2019	2013	(1)
Prudential Center	Office	Boston, MA	—		92,077		948,357		718,028		115,639		1,510,834		231		131,758		1,758,462		721,498		1965/1993/2002/2016-2017	1998/1999/2000	(1)
Embarcadero Center	Office	San Francisco, CA	—		179,697		847,410		499,451		195,986		1,330,572		—		—		1,526,558		736,748		1970/1989	1998-1999	(1)
399 Park Avenue	Office	New York, NY	—		339,200		700,358		393,821		354,107		1,079,272		—		—		1,433,379		445,239		1961/2018	2002	(1)
601 Lexington Avenue	Office	New York, NY	987,858		241,600		494,782		515,644		289,639		962,387		—		—		1,252,026		348,892		1977/1997/2021	2001	(1)
Salesforce Tower	Office	San Francisco, CA	—		200,349		946,205		7,462		200,349		953,667		—		—		1,154,016		129,281		2018	2013	(1)
200 Clarendon Street and Garage	Office	Boston, MA	—		219,543		667,884		235,129		250,512		872,044		—		—		1,122,556		310,318		1976	2010	(1)
250 West 55th Street	Office	New York, NY	—		285,263		603,167		51,800		285,263		654,967		—		—		940,230		179,143		2014	2007	(1)
100 Federal Street	Office	Boston, MA	—		131,067		435,954		119,341		131,067		555,295		—		—		686,362		157,368		1971-1975/2017	2012	(1)
Madison Centre	Office	Seattle, WA	—		104,641		564,336		2,879		104,641		567,215		—		—		671,856		13,611		2017	2022	(1)
Times Square Tower	Office	New York, NY	—		165,413		380,438		121,437		169,193		498,095		—		—		667,288		241,474		2004	2000	(1)
Carnegie Center	Office	Princeton, NJ	—		142,666		316,856		168,261		94,243		476,990		55,919		631		627,783		252,390		1983-2016	1998/1999/2000/2007/2014/2017/2019	(1)
125 Broadway	Office	Cambridge, MA	—		126,364		433,662		58		126,364		433,720		—		—		560,084		4,503		2000	2022	(1)
Atlantic Wharf	Office	Boston, MA	—		63,988		454,537		24,158		63,988		478,695		—		—		542,683		171,876		2011	2007	(1)
Reston Next	Office	Reston, VA	—		2,901		525,277		—		2,901		525,277		—		—		528,178		15,293		2022	1998	(1)
599 Lexington Avenue	Office	New York, NY	—		81,040		100,507		245,609		87,852		339,304		—		—		427,156		182,121		1986	1997	(1)
Fountain Square	Office	Reston, VA	—		56,853		306,298		39,288		56,853		345,586		—		—		402,439		104,864		1986-1990	2012	(1)
510 Madison Avenue	Office	New York, NY	—		103,000		253,665		31,682		103,000		285,347		—		—		388,347		95,520		2012	2010	(1)
325 Main Street	Office	Cambridge, MA	—		21,596		312,492		—		21,596		312,492		—		—		334,088		4,308		2022	1997	(1)
680 Folsom Street	Office	San Francisco, CA	—		72,545		219,766		8,026		72,545		227,792		—		—		300,337		72,414		2014	2012	(1)
145 Broadway	Office	Cambridge, MA	—		121		273,013		26,184		23,367		275,951		—		—		299,318		26,881		2019	1997	(1)
2200 Pennsylvania Avenue	Office	Washington, DC	—		—		183,541		113,108		104,329		192,320		—		—		296,649		71,410		2011	2008	(1)
South of Market and Democracy Tower	Office	Reston, VA	—		13,603		237,479		28,991		13,687		266,386		—		—		280,073		98,665		2008-2009	2003	(1)
Bay Colony Corporate Center	Office	Waltham, MA	—		18,789		148,451		87,804		18,789		231,828		4,427		—		255,044		105,172		1985-1989	2011	(1)
535 Mission Street	Office	San Francisco, CA	—		40,933		148,378		3,852		40,934		152,229		—		—		193,163		42,776		2015	2013	(1)
Mountain View Research Park	Office	Mountain View, CA	—		95,066		68,373		21,270		95,066		89,643		—		—		184,709		28,575		1977-1981/2007-2013	2013	(1)
Reservoir Place	Office	Waltham, MA	—		18,605		104,124		55,359		20,108		156,915		1,065		—		178,088		85,394		1955/1987/2017	1997/1998	(1)


Boston Properties, Inc. Schedule 3—Real Estate and Accumulated Depreciation December 31, 2022 (dollars in thousands)
Property Name	Type	Location	Encumbrances	Original		Costs Capitalized Subsequent to Acquisition	Land and Improvements	Building and Improvements	Land Held for Development	Development and Construction in Progress	Total	Accumulated Depreciation	Year(s) Built/Renovated	Year(s) Acquired	Depreciable Lives (Years)

				Land	Building
1330 Connecticut Avenue	Office	Washington, DC	—	25,982	82,311	38,047	27,135	119,205	—	—	146,340	48,273	1984/2018	2004	(1)
One Freedom Square	Office	Reston, VA	—	9,929	84,504	51,743	11,293	134,883	—	—	146,176	66,084	2000	2003	(1)
880 Winter Street	Office	Waltham, MA	—	15,597	37,255	91,537	15,597	128,792	—	—	144,389	2,560	1998/2022	2019	(1)
Kingstowne Towne Center	Office	Alexandria, VA	—	18,021	109,038	3,822	18,062	112,819	—	—	130,881	52,543	2003-2006	2007	(1)
140 Kendrick Street	Office	Needham, MA	—	18,095	66,905	42,528	19,092	102,625	—	5,811	127,528	41,627	2000	2004	(1)
Shady Grove Innovation District	Office	Rockville, MD	—	52,030	64,212	7,219	26,834	34,988	61,639	—	123,461	3,319	1968-1985	2021	(1)
One and Two Reston Overlook	Office	Reston, VA	—	16,456	66,192	40,516	16,179	106,985	—	—	123,164	57,631	1999	2000	(1)
Weston Corporate Center	Office	Weston, MA	—	25,753	92,312	968	25,854	93,179	—	—	119,033	38,385	2010	2001	(1)
17Fifty Presidents Street	Office	Reston, VA	—	—	113,362	162	—	113,524	—	—	113,524	12,232	2020	2013	(1)
Discovery Square	Office	Reston, VA	—	11,198	71,782	21,618	12,533	92,065	—	—	104,598	54,116	2001	2003	(1)
355 Main Street	Office	Cambridge, MA	—	18,863	53,346	25,418	21,173	76,454	—	—	97,627	34,399	1981/1996/2013	2006	(1)
10 CityPoint	Office	Waltham, MA	—	1,953	85,752	6,406	2,290	91,821	—	—	94,111	20,616	2016	1997	(1)
Two Freedom Square	Office	Reston, VA	—	13,930	77,739	317	15,420	76,566	—	—	91,986	35,850	2001	2003	(1)
200 West Street	Office	Waltham, MA	—	16,148	24,983	49,264	16,813	73,265	317	—	90,395	23,428	1999/2021	1997	(1)
90 Broadway	Office	Cambridge, MA	—	19,104	52,078	18,876	20,785	69,273	—	—	90,058	29,294	1983/1998/2013	2006	(1)
153 & 211 Second Avenue	Office	Waltham, MA	—	33,233	55,940	202	33,233	55,940	202	—	89,375	4,808	1964-2006	2021	(1)
230 CityPoint	Office	Waltham, MA	—	13,189	49,823	24,604	13,807	73,809	—	—	87,616	38,306	1992	2005	(1)
20 CityPoint	Office	Waltham, MA	—	4,887	72,764	7,072	4,887	79,836	—	—	84,723	9,606	2020	2007	(1)
Waltham Weston Corporate Center	Office	Waltham, MA	—	10,385	60,694	12,859	11,097	72,841	—	—	83,938	42,839	2003	1999	(1)
77 CityPoint	Office	Waltham, MA	—	13,847	60,383	9,701	14,023	69,908	—	—	83,931	32,578	2008	2001	(1)
Sumner Square	Office	Washington, DC	—	624	28,745	49,302	28,205	50,466	—	—	78,671	31,436	1985	1999	(1)
2440 West El Camino Real	Office	Mountain View, CA	—	16,741	51,285	6,391	16,741	57,676	—	—	74,417	19,375	1987/2003	2011	(1)
300 Binney Street	Office	Cambridge, MA	—	18,080	51,262	1,268	18,080	51,402	1,128	—	70,610	18,995	2013	2009	(1)
Reston Corporate Center	Office	Reston, VA	—	9,135	50,857	5,579	10,148	55,423	—	—	65,571	33,822	1984	1998	(1)
Wisconsin Place	Office	Chevy Chase, MD	—	—	53,349	11,204	—	64,553	—	—	64,553	26,659	2009	2004	(1)
255 Main Street	Office	Cambridge, MA	—	134	25,110	33,597	548	58,293	—	—	58,841	42,204	1987	1997	(1)
University Place	Office	Cambridge, MA	—	—	37,091	15,903	5,425	47,569	—	—	52,994	35,296	1985	1998	(1)
890 Winter Street	Office	Waltham, MA	—	13,913	28,557	6,998	13,913	35,555	—	—	49,468	5,409	1999	2019	(1)
Capital Gallery	Office	Washington, DC	—	4,725	29,565	9,544	8,662	35,172	—	—	43,834	22,415	1981/2006	2007	(1)
North First Business Park	Office	San Jose, CA	—	23,398	13,069	5,288	23,378	18,377	—	—	41,755	17,270	1981	2007	(1)
150 Broadway	Office	Cambridge, MA	—	850	25,042	15,726	1,323	40,295	—	—	41,618	16,841	1999	1997	(1)
105 Broadway	Office	Cambridge, MA	—	1,299	12,943	12,718	2,390	24,570	—	—	26,960	15,578	1990	1997	(1)
Lexington Office Park	Office	Lexington, MA	—	998	1,426	19,842	1,263	19,551	1,452	—	22,266	16,716	1982	1997	(1)
The Point	Office	Waltham, MA	—	6,395	10,040	546	6,492	10,489	—	—	16,981	2,308	2015	2007	(1)
690 Folsom Street	Office	San Francisco, CA	—	3,219	11,038	1,877	3,219	12,915	—	—	16,134	3,838	2015	2012	(1)
33 Hayden Avenue	Office	Lexington, MA	—	266	3,234	11,501	425	14,576	—	—	15,001	7,929	1979	1997	(1)


Boston Properties, Inc. Schedule 3—Real Estate and Accumulated Depreciation December 31, 2022 (dollars in thousands)
Property Name	Type	Location	Encumbrances			Original				Costs Capitalized Subsequent to Acquisition		Land and Improvements			Building and Improvements			Land Held for Development			Development and Construction in Progress		Total		Accumulated Depreciation		Year(s) Built/Renovated	Year(s) Acquired	Depreciable Lives (Years)

						Land		Building
Avant Retail	Office	Reston, VA	—			1,499		6,647		2,577		1,499			9,224			—			—		10,723		3,210		2014	2010	(1)
92-100 Hayden Avenue	Office	Lexington, MA	—			594		6,748		2,297		778			8,861			—			—		9,639		7,507		1985	1997	(1)
32 Hartwell Avenue	Office	Lexington, MA	—			168		1,943		6,944		314			8,741			—			—		9,055		3,103		1968/1979/1987	1997	(1)
250 Binney Street	Office	Cambridge, MA	—			110		4,483		3,593		273			7,913			—			—		8,186		6,974		1983	1997	(1)
453 Ravendale Drive	Office	Mountain View, CA	—			5,477		1,090		677		5,477			1,767			—			—		7,244		964		1977	2012	(1)
17 Hartwell Avenue	Office	Lexington, MA	—			26		150		6,064		65			6,175			—			—		6,240		3,530		1968	1997	(1)
The Skylyne	Residential	Oakland, CA	—			28,962		239,077		1,784		28,962			240,861			—			—		269,823		14,154		2020	N/A	(1)
Signature at Reston	Residential	Reston, VA	—			27,076		190,580		1,667		27,076			192,247			—			—		219,323		23,353		2018	2013	(1)
Proto Kendall Square	Residential	Cambridge, MA	—			9,243		127,248		3,336		9,245			130,582			—			—		139,827		14,508		2018	2015	(1)
The Lofts at Atlantic Wharf	Residential	Boston, MA	—			3,529		54,891		2,356		3,529			57,247			—			—		60,776		17,174		2011	2007	(1)
Boston Marriott Cambridge	Hotel	Cambridge, MA	—			478		37,918		32,837		1,201			69,521			511			—		71,233		51,568		1986/2017	1997	(1)
Kendall Center Green Garage	Garage	Cambridge, MA	—			—		35,035		6,798		103			41,730			—			—		41,833		17,039		1984	2006	(1)
Kendall Center Yellow Garage	Garage	Cambridge, MA	—			1,256		15,697		1,653		1,434			17,172			—			—		18,606		7,395		2006	2004	(1)
Kendall Center Blue Garage	Garage	Cambridge, MA	—			1,163		11,633		2,111		1,579			13,328			—			—		14,907		13,075		1990	1997	(1)
2100 Pennsylvania Avenue	Development	Washington, DC	—			—		—		472,873		185,203			230,497			—			57,173		472,873		9,755		N/A	N/A	N/A
190 CityPoint (formerly 180 CityPoint)	Development	Waltham, MA	—			—		—		140,370		—			—			—			140,370		140,370		—		N/A	2006	N/A
103 CityPoint	Development	Waltham, MA	—			—		—		44,752		—			—			74			44,678		44,752		—		N/A	2007	N/A
Reston Next Office Phase II	Development	Reston, VA	—			—		—		22,954		—			—			—			22,954		22,954		—		N/A	1998	N/A
Reston Next Retail	Development	Reston, VA	—			—		—		3,199		—			—			—			3,199		3,199		—		N/A	1998	N/A
777 Harrison Street	Land	San Francisco, CA	—			144,647		—		28,239		—			47			172,839			—		172,886		20		N/A	2020	N/A
Kendall Center Master Plan	Land	Cambridge, MA	—			—		—		148,476		—			—			148,476			—		148,476		—		N/A	1997	N/A
Back Bay Station Master Plan	Land	Boston, MA	—			—		—		72,957		—			—			72,957			—		72,957		—		N/A	N/A	N/A
3625-3635 Peterson Way	Land	Santa Clara, CA	—			63,206		—		5,165		—			—			68,371			—		68,371		—		N/A	2016	N/A
North First Master Plan	Land	San Jose, CA	—			35,004		—		3,968		—			—			38,972			—		38,972		—		N/A	2007	N/A
Plaza at Almaden	Land	San Jose, CA	—			—		—		38,090		—			—			38,090			—		38,090		—		N/A	2006	N/A
Springfield Metro Center	Land	Springfield, VA	—			—		—		19,891		—			—			19,891			—		19,891		—		N/A	2007	N/A
CityPoint South Master Plan	Land	Waltham, MA	—			—		—		19,693		—			—			19,693			—		19,693		—		N/A	N/A	N/A
Reston Gateway Master Plan	Land	Reston, VA	—			—		—		12,734		—			—			12,734			—		12,734		—		N/A	1998	N/A
Weston Quarry	Land	Weston, MA	—			—		—		1,249		—			—			1,249			—		1,249		—		N/A	2001	N/A
Broad Run Business Park	Land	Loudoun County, VA	—			—		—		1,184		—			—			1,184			—		1,184		—		N/A	1998	N/A
Reston Overlook Master Plan	Land	Reston, VA	—			—		—		80		—			—			80			—		80		—		N/A	2000	N/A

			$	3,272,368	(2)	$	5,373,987	$	14,755,092	$	5,615,135	$	5,571,327	(3)	$	19,044,812	(4)	$	721,501	(5)	$	406,574	$	25,744,214	$	6,260,992

Note: Total Real Estate does not include Furniture, Fixtures and Equipment totaling approximately $50,310. Accumulated Depreciation does not include approximately $37,090 of accumulated depreciation related to Furniture, Fixtures and Equipment. Office type includes office, life sciences, and retail properties.

The aggregate cost and accumulated depreciation for tax purposes was approximately $23.1 billion and $5.0 billion, respectively.

(1)Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 40 years.

(2)Includes unamortized deferred financing costs totaling approximately $27,632.

(3)Includes Right of Use Assets - Finance Leases and Right of Use Assets - Operating Leases of approximately $214,165 and $167,351, respectively.

(4)Includes Right of Use Assets - Finance Leases of approximately $23,345.

(5)Includes pre-development costs.

Boston Properties, Inc.

Real Estate and Accumulated Depreciation

December 31, 2022, 2021 and 2020

(dollars in thousands)

A summary of activity for real estate and accumulated depreciation is as follows:


	2022		2021		2020
Real Estate:
Balance at the beginning of the year	$	24,108,220	$	23,303,303	$	22,844,697
Additions to/improvements of real estate	2,228,000		1,145,084		996,989
Assets sold/written-off	(592,006)		(340,167)		(538,383)
Balance at the end of the year	$	25,744,214	$	24,108,220	$	23,303,303
Accumulated Depreciation:
Balance at the beginning of the year	$	5,848,183	$	5,501,637	$	5,239,179
Depreciation expense	646,020		623,854		573,898
Assets sold/written-off	(233,211)		(277,308)		(311,440)
Balance at the end of the year	$	6,260,992	$	5,848,183	$	5,501,637

Note: Real Estate and Accumulated Depreciation amounts do not include Furniture, Fixtures and Equipment.


Boston Properties Limited Partnership Schedule 3—Real Estate and Accumulated Depreciation December 31, 2022 (dollars in thousands)
					Original				Costs Capitalized Subsequent to Acquisition		Land and Improvements		Building and Improvements		Land Held for Development		Development and Construction in Progress		Total		Accumulated Depreciation		Year(s) Built/Renovated	Year(s) Acquired	Depreciable Lives (Years)
Property Name	Type	Location	Encumbrances		Land		Building
767 Fifth Avenue (the General Motors Building)	Office	New York, NY	$	2,284,510	$	1,796,252	$	1,532,654	$	325,762	$	1,796,252	$	1,858,416	$	—	$	—	$	3,654,668	$	457,344	1968/2019	2013	(1)
Prudential Center	Office	Boston, MA	—		92,077		948,357		658,972		100,541		1,466,876		231		131,758		1,699,406		702,725		1965/1993/2002/2016-2017	1998/1999/2000	(1)
Embarcadero Center	Office	San Francisco, CA	—		179,697		847,410		437,070		180,419		1,283,758		—		—		1,464,177		716,657		1970/1989	1998-1999	(1)
399 Park Avenue	Office	New York, NY	—		339,200		700,358		334,213		339,200		1,034,571		—		—		1,373,771		426,148		1961/2018	2002	(1)
601 Lexington Avenue	Office	New York, NY	987,858		241,600		494,782		478,558		279,281		935,659		—		—		1,214,940		337,421		1977/1997/2021	2001	(1)
Salesforce Tower	Office	San Francisco, CA	—		200,349		946,205		7,462		200,349		953,667		—		—		1,154,016		129,281		2018	2013	(1)
200 Clarendon Street and Garage	Office	Boston, MA	—		219,543		667,884		235,129		250,512		872,044		—		—		1,122,556		310,318		1976	2010	(1)
250 West 55th Street	Office	New York, NY	—		285,263		603,167		51,800		285,263		654,967		—		—		940,230		179,143		2014	2007	(1)
100 Federal Street	Office	Boston, MA	—		131,067		435,954		119,341		131,067		555,295		—		—		686,362		157,368		1971-1975/2017	2012	(1)
Madison Centre	Office	Seattle, WA	—		104,641		564,336		2,879		104,641		567,215						671,856		13,611		2017	2022	(1)
Times Square Tower	Office	New York, NY	—		165,413		380,438		83,458		159,694		469,615		—		—		629,309		229,310		2004	2000	(1)
Carnegie Center	Office	Princeton, NJ	—		142,666		316,856		153,298		90,501		465,769		55,919		631		612,820		247,525		1983-2016	1998/1999/2000/2007/2014/2017/2019	(1)
125 Broadway	Office	Cambridge, MA	—		126,364		433,662		58		126,364		433,720		—		—		560,084		4,503		2000	2022	(1)
Atlantic Wharf	Office	Boston, MA	—		63,988		454,537		24,158		63,988		478,695		—		—		542,683		171,876		2011	2007	(1)
Reston Next	Office	Reston, VA	—		2,901		525,277		—		2,901		525,277		—		—		528,178		15,293		2022	1998	(1)
599 Lexington Avenue	Office	New York, NY	—		81,040		100,507		218,367		81,040		318,874		—		—		399,914		173,396		1986	1997	(1)
Fountain Square	Office	Reston, VA	—		56,853		306,298		39,288		56,853		345,586		—		—		402,439		104,864		1986-1990	2012	(1)
510 Madison Avenue	Office	New York, NY	—		103,000		253,665		31,682		103,000		285,347		—		—		388,347		95,520		2012	2010	(1)
325 Main Street	Office	Cambridge, MA	—		21,596		312,492		(193)		21,403		312,492		—		—		333,895		4,308		2022	1997	(1)
680 Folsom Street	Office	San Francisco, CA	—		72,545		219,766		8,026		72,545		227,792		—		—		300,337		72,414		2014	2012	(1)
145 Broadway	Office	Cambridge, MA	—		121		273,013		25,981		23,164		275,951		—		—		299,115		26,881		2019	1997	(1)
2200 Pennsylvania Avenue	Office	Washington, DC	—		—		183,541		113,108		104,329		192,320		—		—		296,649		71,410		2011	2008	(1)
South of Market and Democracy Tower	Office	Reston, VA	—		13,603		237,479		28,655		13,603		266,134		—		—		279,737		98,574		2008-2009	2003	(1)
Bay Colony Corporate Center	Office	Waltham, MA	—		18,789		148,451		87,804		18,789		231,828		4,427		—		255,044		105,172		1985-1989	2011	(1)
535 Mission Street	Office	San Francisco, CA	—		40,933		148,378		3,852		40,934		152,229		—		—		193,163		42,776		2015	2013	(1)
Mountain View Research Park	Office	Mountain View, CA	—		95,066		68,373		21,270		95,066		89,643		—		—		184,709		28,575		1977-1981/2007-2013	2013	(1)
Reservoir Place	Office	Waltham, MA	—		18,605		104,124		51,284		19,089		153,859		1,065		—		174,013		84,089		1955/1987/2017	1997/1998	(1)
1330 Connecticut Avenue	Office	Washington, DC	—		25,982		82,311		33,434		25,982		115,745		—		—		141,727		46,795		1984/2018	2004	(1)
One Freedom Square	Office	Reston, VA	—		9,929		84,504		46,106		9,883		130,656		—		—		140,539		64,278		2000	2003	(1)
880 Winter Street	Office	Waltham, MA	—		15,597		37,255		91,537		15,597		128,792		—		—		144,389		2,560		1998/2022	2019	(1)
Kingstowne Towne Center	Office	Alexandria, VA	—		18,021		109,038		3,658		18,021		112,696		—		—		130,717		52,498		2003-2006	2007	(1)
140 Kendrick Street	Office	Needham, MA	—		18,095		66,905		38,538		18,095		99,632		—		5,811		123,538		40,368		2000	2004	(1)


Boston Properties Limited Partnership Schedule 3—Real Estate and Accumulated Depreciation December 31, 2022 (dollars in thousands)
				Original		Costs Capitalized Subsequent to Acquisition	Land and Improvements	Building and Improvements	Land Held for Development	Development and Construction in Progress	Total	Accumulated Depreciation	Year(s) Built/Renovated	Year(s) Acquired	Depreciable Lives (Years)
Property Name	Type	Location	Encumbrances	Land	Building
Shady Grove Innovation District	Office	Rockville, MD	—	52,030	64,212	7,219	26,834	34,988	61,639	—	123,461	3,319	1968-1985	2021	(1)
One and Two Reston Overlook	Office	Reston, VA	—	16,456	66,192	36,098	15,074	103,672	—	—	118,746	56,216	1999	2000	(1)
Weston Corporate Center	Office	Weston, MA	—	25,753	92,312	968	25,854	93,179	—	—	119,033	38,385	2010	2001	(1)
17Fifty Presidents Street	Office	Reston, VA	—	—	113,362	162	—	113,524	—	—	113,524	12,232	2020	2013	(1)
Discovery Square	Office	Reston, VA	—	11,198	71,782	16,073	11,146	87,907	—	—	99,053	52,341	2001	2003	(1)
355 Main Street	Office	Cambridge, MA	—	18,863	53,346	25,120	21,098	76,231	—	—	97,329	34,306	1981/1996/2013	2006	(1)
10 CityPoint	Office	Waltham, MA	—	1,953	85,752	6,243	2,127	91,821	—	—	93,948	20,616	2016	1997	(1)
Two Freedom Square	Office	Reston, VA	—	13,930	77,739	(5,895)	13,866	71,908	—	—	85,774	33,860	2001	2003	(1)
200 West Street	Office	Waltham, MA	—	16,148	24,983	46,603	16,148	71,269	317	—	87,734	22,576	1999/2021	1997	(1)
90 Broadway	Office	Cambridge, MA	—	19,104	52,078	18,697	20,741	69,138	—	—	89,879	29,243	1983/1998/2013	2006	(1)
153 & 211 Second Avenue	Office	Waltham, MA	—	33,233	55,940	202	33,233	55,940	202	—	89,375	4,808	1964-2006	2021	(1)
230 CityPoint	Office	Waltham, MA	—	13,189	49,823	22,987	13,403	72,596	—	—	85,999	37,791	1992	2005	(1)
20 CityPoint	Office	Waltham, MA	—	4,887	72,764	7,072	4,887	79,836	—	—	84,723	9,606	2020	2007	(1)
Waltham Weston Corporate Center	Office	Waltham, MA	—	10,385	60,694	9,872	10,350	70,601	—	—	80,951	41,883	2003	1999	(1)
77 CityPoint	Office	Waltham, MA	—	13,847	60,383	9,596	13,997	69,829	—	—	83,826	32,548	2008	2001	(1)
Sumner Square	Office	Washington, DC	—	624	28,745	47,222	27,685	48,906	—	—	76,591	30,773	1985	1999	(1)
2440 West El Camino Real	Office	Mountain View, CA	—	16,741	51,285	6,391	16,741	57,676	—	—	74,417	19,375	1987/2003	2011	(1)
300 Binney Street	Office	Cambridge, MA	—	18,080	51,262	1,268	18,080	51,402	1,128	—	70,610	18,995	2013	2009	(1)
Reston Corporate Center	Office	Reston, VA	—	9,135	50,857	2,968	9,496	53,464	—	—	62,960	32,986	1984	1998	(1)
Wisconsin Place	Office	Chevy Chase, MD	—	—	53,349	11,204	—	64,553	—	—	64,553	26,659	2009	2004	(1)
255 Main Street	Office	Cambridge, MA	—	134	25,110	31,941	134	57,051	—	—	57,185	41,677	1987	1997	(1)
University Place	Office	Cambridge, MA	—	—	37,091	14,453	5,425	46,119	—	—	51,544	34,270	1985	1998	(1)
890 Winter Street	Office	Waltham, MA	—	13,913	28,557	6,998	13,913	35,555	—	—	49,468	5,409	1999	2019	(1)
Capital Gallery	Office	Washington, DC	—	4,725	29,565	4,882	6,128	33,044	—	—	39,172	21,506	1981/2006	2007	(1)
North First Business Park	Office	San Jose, CA	—	23,398	13,069	5,265	23,372	18,360	—	—	41,732	17,264	1981	2007	(1)
150 Broadway	Office	Cambridge, MA	—	850	25,042	13,721	822	38,791	—	—	39,613	16,195	1999	1997	(1)
105 Broadway	Office	Cambridge, MA	—	1,299	12,943	10,611	1,862	22,991	—	—	24,853	14,898	1990	1997	(1)
Lexington Office Park	Office	Lexington, MA	—	998	1,426	19,078	1,072	18,978	1,452	—	21,502	16,474	1982	1997	(1)
The Point	Office	Waltham, MA	—	6,395	10,040	546	6,492	10,489	—	—	16,981	2,308	2015	2007	(1)
690 Folsom Street	Office	San Francisco, CA	—	3,219	11,038	1,877	3,219	12,915	—	—	16,134	3,838	2015	2012	(1)
33 Hayden Avenue	Office	Lexington, MA	—	266	3,234	10,864	266	14,098	—	—	14,364	7,725	1979	1997	(1)
Avant Retail	Office	Reston, VA	—	1,499	6,647	2,577	1,499	9,224	—	—	10,723	3,210	2014	2010	(1)
92-100 Hayden Avenue	Office	Lexington, MA	—	594	6,748	1,568	595	8,315	—	—	8,910	7,273	1985	1997	(1)
32 Hartwell Avenue	Office	Lexington, MA	—	168	1,943	6,358	168	8,301	—	—	8,469	2,915	1968/1979/1987	1997	(1)
250 Binney Street	Office	Cambridge, MA	—	110	4,483	2,939	110	7,422	—	—	7,532	6,769	1983	1997	(1)


Boston Properties Limited Partnership Schedule 3—Real Estate and Accumulated Depreciation December 31, 2022 (dollars in thousands)
						Original				Costs Capitalized Subsequent to Acquisition		Land and Improvements			Building and Improvements			Land Held for Development			Development and Construction in Progress		Total		Accumulated Depreciation		Year(s) Built/Renovated	Year(s) Acquired	Depreciable Lives (Years)
Property Name	Type	Location	Encumbrances			Land		Building
453 Ravendale Drive	Office	Mountain View, CA	—			5,477		1,090		677		5,477			1,767			—			—		7,244		964		1977	2012	(1)
17 Hartwell Avenue	Office	Lexington, MA	—			26		150		5,907		26			6,057			—			—		6,083		3,479		1968	1997	(1)
The Skylyne	Residential	Oakland, CA	—			28,962		239,077		1,784		28,962			240,861			—			—		269,823		14,154		2020	N/A	(1)
Signature at Reston	Residential	Reston, VA	—			27,076		190,580		1,667		27,076			192,247			—			—		219,323		23,353		2018	2013	(1)
Proto Kendall Square	Residential	Cambridge, MA	—			9,243		127,248		3,336		9,245			130,582			—			—		139,827		14,508		2018	2015	(1)
The Lofts at Atlantic Wharf	Residential	Boston, MA	—			3,529		54,891		2,356		3,529			57,247			—			—		60,776		17,174		2011	2007	(1)
Boston Marriott Cambridge	Hotel	Cambridge, MA	—			478		37,918		29,946		478			67,353			511			—		68,342		50,642		1986/2017	1997	(1)
Kendall Center Green Garage	Garage	Cambridge, MA	—			—		35,035		6,384		—			41,419			—			—		41,419		16,909		1984	2006	(1)
Kendall Center Yellow Garage	Garage	Cambridge, MA	—			1,256		15,697		941		1,256			16,638			—			—		17,894		7,170		2006	2004	(1)
Kendall Center Blue Garage	Garage	Cambridge, MA	—			1,163		11,633		446		1,163			12,079			—			—		13,242		12,006		1990	1997	(1)
2100 Pennsylvania Avenue	Development	Washington, DC	—			—		—		472,873		185,203			230,497			—			57,173		472,873		9,755		N/A	N/A	N/A
190 CityPoint (formerly 180 CityPoint)	Development	Waltham, MA	—			—		—		140,370		—			—			—			140,370		140,370		—		N/A	2006	N/A
103 CityPoint	Development	Waltham, MA	—			—		—		44,752		—			—			74			44,678		44,752		—		N/A	2007	N/A
Reston Next Office Phase II	Development	Reston, VA	—			—		—		22,954		—			—			—			22,954		22,954		—		N/A	1998	N/A
Reston Next Retail	Development	Reston, VA	—			—		—		3,199		—			—			—			3,199		3,199		—		N/A	1998	N/A
777 Harrison Street	Land	San Francisco, CA	—			144,647		—		28,239		—			47			172,839			—		172,886		20		N/A	2020	N/A
Kendall Center Master Plan	Land	Cambridge, MA	—			—		—		148,476		—			—			148,476			—		148,476		—		N/A	1997	N/A
Back Bay Station Master Plan	Land	Boston, MA	—			—		—		72,957		—			—			72,957			—		72,957		—		N/A	N/A	N/A
3625-3635 Peterson Way	Land	Santa Clara, CA	—			63,206		—		5,165		—			—			68,371			—		68,371		—		N/A	2016	N/A
North First Master Plan	Land	San Jose, CA	—			35,004		—		3,968		—			—			38,972			—		38,972		—		N/A	2007	N/A
Plaza at Almaden	Land	San Jose, CA	—			—		—		38,090		—			—			38,090			—		38,090		—		N/A	2006	N/A
Springfield Metro Center	Land	Springfield, VA	—			—		—		19,891		—			—			19,891			—		19,891		—		N/A	2007	N/A
CityPoint South Master Plan	Land	Waltham, MA	—			—		—		19,693		—			—			19,693			—		19,693		—		N/A	N/A	N/A
Reston Gateway Master Plan	Land	Reston, VA	—			—		—		12,734		—			—			12,734			—		12,734		—		N/A	1998	N/A
Weston Quarry	Land	Weston, MA	—			—		—		1,249		—			—			1,249			—		1,249		—		N/A	2001	N/A
Broad Run Business Park	Land	Loudoun County, VA	—			—		—		1,184		—			—			1,184			—		1,184		—		N/A	1998	N/A
Reston Overlook Master Plan	Land	Reston, VA	—			—		—		80		—			—			80			—		80		—		N/A	2000	N/A

			$	3,272,368	(2)	$	5,373,987	$	14,755,092	$	5,247,621	$	5,476,618	(3)	$	18,772,007	(4)	$	721,501	(5)	$	406,574	$	25,376,700	$	6,143,384

The aggregate cost and accumulated depreciation for tax purposes was approximately $25.7 billion and $5.6 billion, respectively.

(1)Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 40 years.

(2)Includes unamortized deferred financing costs totaling approximately $27,632.

(3)Includes Right of Use Assets - Finance Leases and Right of Use Assets - Operating Leases of approximately $214,165 and $167,351, respectively.

(4)Includes Right of Use Assets - Finance Leases of approximately $23,345.

(5)Includes pre-development costs.

Boston Properties Limited Partnership

Real Estate and Accumulated Depreciation

December 31, 2022, 2021 and 2020

(dollars in thousands)

A summary of activity for real estate and accumulated depreciation is as follows:


	2022		2021		2020
Real Estate:
Balance at the beginning of the year	$	23,734,833	$	22,926,494	$	22,449,476
Additions to/improvements of real estate	2,228,000		1,145,084		996,989
Assets sold/written-off	(586,133)		(336,745)		(519,971)
Balance at the end of the year	$	25,376,700	$	23,734,833	$	22,926,494
Accumulated Depreciation:
Balance at the beginning of the year	$	5,736,240	$	5,396,111	$	5,135,289
Depreciation expense	638,538		615,553		566,813
Assets sold/written-off	(231,394)		(275,424)		(305,991)
Balance at the end of the year	$	6,143,384	$	5,736,240	$	5,396,111

Note: Real Estate and Accumulated Depreciation amounts do not include Furniture, Fixtures and Equipment.

Real Estate Asset Acquisition (Details) - USD ($) $ in Thousands	Sep. 16, 2022	May 17, 2022
Madison Centre
Asset Acquisition [Line Items]
Land		$ 104,641
Building and improvements		505,766
Tenant Improvements		58,570
Net Assets Acquired		724,255
Madison Centre \| In-Place Lease Intangibles
Asset Acquisition [Line Items]
Lease Intangibles		74,598
Madison Centre \| Above Market Lease Intangibles [Member]
Asset Acquisition [Line Items]
Lease Intangibles		3,794
Madison Centre \| Below Market Lease Intangible [Member]
Asset Acquisition [Line Items]
Lease Intangibles		$ (23,114)
125 Broadway
Asset Acquisition [Line Items]
Land	$ 126,364
Building and improvements	403,588
Tenant Improvements	30,074
Net Assets Acquired	592,438
125 Broadway \| In-Place Lease Intangibles
Asset Acquisition [Line Items]
Lease Intangibles	49,137
125 Broadway \| Below Market Lease Intangible [Member]
Asset Acquisition [Line Items]
Lease Intangibles	$ (16,725)

Earnings Per Share / Common Unit

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Earnings Per Share / Common Unit

12. Earnings Per Share / Common Unit

BXP

The following table provides a reconciliation of both the net income attributable to Boston Properties, Inc. common shareholders and the number of common shares used in the computation of basic earnings per share (“EPS”), which is calculated by dividing net income attributable to Boston Properties, Inc. common shareholders by the weighted-average number of common shares outstanding during the period. Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are also participating securities. As such, unvested restricted common stock of BXP and BPLP’s LTIP Units, 2012 OPP Units and MYLTIP Units are considered participating securities. Participating securities are included in the computation of basic EPS of BXP using the two-class method. Participating securities are included in the computation of diluted EPS of BXP using the if-converted method if the impact is dilutive. Because the 2012 OPP Units and 2013 - 2019 MYLTIP Units required, and the 2020 - 2022 MYLTIP Units require, BXP to outperform absolute and/or relative return thresholds, unless such thresholds have been met by the end of the applicable reporting period, BXP excludes such units from the diluted EPS calculation. Other potentially dilutive common shares, including stock options, restricted stock and other securities of BPLP that are exchangeable for BXP’s Common Stock, and the related impact on earnings, are considered when calculating diluted EPS.


	Year ended December 31, 2022
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	848,947	156,726	$	5.42
Allocation of undistributed earnings to participating securities	(891)		—	(0.01)
Net income attributable to Boston Properties, Inc. common shareholders	848,056		156,726	5.41
Effect of Dilutive Securities:
Stock Based Compensation	—		411	(0.01)
Diluted Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	848,056	157,137	$	5.40

	Year ended December 31, 2021
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	496,223	156,116	$	3.18
Allocation of undistributed earnings to participating securities	—		—	—
Net income attributable to Boston Properties, Inc. common shareholders	$	496,223	156,116	$	3.18
Effect of Dilutive Securities:
Stock Based Compensation	—		260	(0.01)
Diluted Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	496,223	156,376	$	3.17

	Year ended December 31, 2020
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	862,227	155,432	$	5.55
Allocation of undistributed earnings to participating securities	(748)		—	(0.01)
Net income attributable to Boston Properties, Inc. common shareholders	$	861,479	155,432	$	5.54
Effect of Dilutive Securities:
Stock Based Compensation	—		85	—
Diluted Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	861,479	155,517	$	5.54

BPLP

The following table provides a reconciliation of both the net income attributable to Boston Properties Limited Partnership common unitholders and the number of common units used in the computation of basic earnings per common unit, which is calculated by dividing net income attributable to Boston Properties Limited Partnership common unitholders by the weighted-average number of common units outstanding during the period. Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are also participating securities. As such, unvested restricted common stock of BXP and BPLP’s LTIP Units, 2012 OPP Units and MYLTIP Units are considered participating securities. Participating securities are included in the computation of basic earnings per common unit using the two-class method. Participating securities are included in the computation of diluted earnings per common unit using the if-converted method if the impact is dilutive. Because the 2012 OPP Units and 2013 - 2019 MYLTIP Units required, and the 2020 - 2022 MYLTIP Units require, BXP to outperform absolute and/or relative return thresholds, unless such thresholds have been met by the end of the applicable reporting period, BPLP excludes such units from the diluted earnings per common unit calculation. Other potentially dilutive common units and the related impact on earnings are considered when calculating diluted earnings per common unit. Included in the number of units (the denominator) below are approximately 17,634,000, 17,034,000 and 17,211,000 redeemable common units for the years ended December 31, 2022, 2021 and 2020, respectively.


	Year ended December 31, 2022
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	957,265	174,360	$	5.49
Allocation of undistributed earnings to participating securities	(991)		—	(0.01)
Net income attributable to Boston Properties Limited Partnership common unitholders	$	956,274	174,360	$	5.48
Effect of Dilutive Securities:
Stock Based Compensation	—		411	(0.01)
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	956,274	174,771	$	5.47

	Year ended December 31, 2021
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	561,993	173,150	$	3.25
Allocation of undistributed earnings to participating securities	—		—	—
Net income attributable to Boston Properties Limited Partnership common unitholders	$	561,993	173,150	$	3.25
Effect of Dilutive Securities:
Stock Based Compensation	—		260	(0.01)
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	561,993	173,410	$	3.24


	Year ended December 31, 2020
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	979,979	172,643	$	5.68
Allocation of undistributed earnings to participating securities	(830)		—	(0.01)
Net income attributable to Boston Properties Limited Partnership common unitholders	$	979,149	172,643	$	5.67
Effect of Dilutive Securities:
Stock Based Compensation	—		85	—
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	979,149	172,728	$	5.67

Consolidated Statements Of Comprehensive Income - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Net income

$ 1,020,584

$ 631,932

$ 1,018,691

Other comprehensive income :

Effective portion of interest rate contracts

19,396

8,544

(7,848)

Amortization of interest rate contracts

^[1]

6,707

6,704

6,697

Other comprehensive income (loss)

26,103

15,248

(1,151)

Comprehensive Income

1,046,687

647,180

1,017,540

Net income attributable to noncontrolling interests

(171,637)

(126,737)

(145,964)

Other comprehensive income attributable to noncontrolling interests

(3,156)

(2,020)

(404)

Comprehensive income attributable to the Company

871,894

518,423

871,172

Boston Properties Limited Partnership

Net income

1,032,122

641,771

1,038,739

Other comprehensive income :

Effective portion of interest rate contracts

19,396

8,544

(7,848)

Amortization of interest rate contracts

^[2]

6,707

6,704

6,697

Other comprehensive income (loss)

26,103

15,248

(1,151)

Comprehensive Income

1,058,225

657,019

1,037,588

Net income attributable to noncontrolling interests

(75,433)

(71,382)

(48,836)

Comprehensive income attributable to the Company

$ 982,792

$ 585,637

$ 988,752

[1]	Amounts reclassified from comprehensive income primarily to interest expense within Boston Properties, Inc.’s Consolidated Statements of Operations
[2]	Amounts reclassified from comprehensive income primarily to interest expense within Boston Properties Limited Partnership’s Consolidated Statements of Operations.

Stockholders' Equity / Partners' Capital Narrative (Details) $ / shares in Units, $ in Thousands					12 Months Ended
	Apr. 01, 2021	Mar. 31, 2021 USD ($)	Mar. 02, 2021 USD ($) $ / shares shares	May 22, 2020 USD ($) yr	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) $ / shares shares	Mar. 27, 2018 $ / shares	Jun. 02, 2017 USD ($)
Class of Stock [Line Items]
Common Stock, Shares, Outstanding					156,757,867	156,544,849
General Partners' Capital Account, Units Outstanding (in units)					1,749,682
Limited Partners' Capital Account, Units Outstanding (in units)					155,008,185
Options exercised					0	247,920
Shares of Common Stock issued in connection with redemption of an equal number of OP Units (in shares)					182,929	523,969
Series B, Shares Outstanding (in shares)					0	0
Preferred Stock Redemption Premium \| $					$ 0	$ 6,412	$ 0
ATM Program [Member]
Class of Stock [Line Items]
At The Market Stock Offering Program Aggregate Value Of Common Stock \| $				$ 600,000					$ 600,000
At Market Stock Offering Program Maximum Length Of Sale (in years) \| yr				3
Series B Cumulative Redeemable Preferred Stock / Unit [Member]
Class of Stock [Line Items]
Series B, Shares Outstanding (in shares)			80,000				80,000
Series B Liquidation Preference Per Share/ Unit \| $ / shares							$ 2,500	$ 2,500
Series B, Dividend Rate, Percentage			5.25%				5.25%
Preferred Stock, Redemption Price Per Share \| $ / shares			$ 2,500
Preferred Stock Redemption Price Per Share, plus accrued and unpaid dividends \| $ / shares			$ 2,516.41
Preferred Stock, Redemption Amount \| $			$ 201,300
Redeemable Preferred Stock Dividends \| $			$ 1,300
Preferred Stock Redemption Premium \| $		$ 6,400
Preferred Stock, Redemption Date	Apr. 01, 2021
Depository shares of Series B Cumulative Redeemable Preferred
Class of Stock [Line Items]
Series B, Shares Outstanding (in shares)							8,000,000
Series B Liquidation Preference Per Share/ Unit \| $ / shares							$ 25.00	$ 25.00

Noncontrolling Interests (Property Partnerships) (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Noncontrolling Interest [Line Items]
Noncontrolling Interest in Limited Partnerships	$ 1,547,317	$ 1,556,553

Stock Option and Incentive Plan

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Stock Option and Incentive Plan

14. Stock Option and Incentive Plan

At BXP’s 2021 annual meeting of stockholders held on May 20, 2021, its stockholders approved the Boston Properties, Inc. 2021 Stock Incentive Plan (the “2021 Plan”). The 2021 Plan replaces the Boston Properties, Inc. 2012 Stock Option and Incentive Plan (the “2012 Plan”) and no further awards will be issued under the 2012 Plan. The material features of the 2021 Plan include, among other things: (i) the maximum number of shares of common stock reserved and available for issuance under the 2021 Plan is 5,400,000 shares less one share for every one share that was granted between March 4, 2021 and May 19, 2021 under the 2012 Plan, (ii) shares of common stock underlying awards granted under the 2021 Plan or the 2012 Plan that are forfeited, canceled or otherwise terminated (other than by exercise) will be added back to the shares of common stock available for issuance under the 2021 Plan and, with respect to “full-value” awards under the 2021 Plan or the 2012 Plan, shares tendered or held back for taxes and shares previously reserved for issuance pursuant to such an award to the extent that such shares are not issued and are no longer issuable pursuant to such an award (e.g., in the event that a full-value award that may be settled in cash or by issuance of shares of common stock is settled in cash) will be added back to the shares available for issuance under the 2021 Plan, (iii) the award of stock options (both incentive and non-qualified options), stock appreciation rights, restricted stock units, restricted stock, unrestricted stock, dividend equivalent rights, cash-based awards and other equity-based awards (including LTIP Units) is permitted, (iv) stock options may not be repriced and “underwater” stock options may not be exchanged for another award or cash

without stockholder approval; and (v) the term of the 2021 Plan is for ten years from the date of stockholder approval.

On February 1, 2022, BXP’s Compensation Committee approved the 2022 MYLTIP awards under the 2021 Plan to certain officers and employees of BXP. The 2022 MYLTIP awards consist of two, equally weighted (50% each) components that utilize BXP’s TSR over a three-year measurement period as the performance metric.

The first component of the 2022 MYLTIP represents one-half (50%) of the target grant-date value of the award. The number of LTIP Units that can be earned under this component ranges from zero to 200% of the target number of LTIP Units, based on BXP’s three-year, annualized relative TSR performance compared to a custom index of peer companies. Under this component, 100% of the target number of LTIP Units will be earned if BXP’s TSR equals the custom index TSR; for relative TSR performance between -1,000 basis points and +1,000 basis points, the number of LTIP Units earned will be determined using linear interpolation.

The second component represents the remaining one-half (50%) of the target grant-date value of the 2022 MYLTIP. The number of LTIP Units that can be earned under this component ranges from zero to 200% of the target number of LTIP Units, based on BXP’s non-annualized, cumulative absolute TSR during the three-year performance period. Under this component, 100% of the target number of LTIP Units will be earned if BXP achieves an absolute TSR equal to +1,000 basis points; if BXP’s absolute TSR is greater than -4,000 basis points but less than +6,000 basis points, then the number of LTIP Units earned will be determined using linear interpolation.

Total earned awards under the 2022 MYLTIP, if any, will equal the sum of the number of LTIP Units earned under the first and second components and will range from zero to a maximum of 254,061 LTIP Units with a target of approximately 127,031 LTIP Units and linear interpolation between zero and maximum. Earned awards (if any) will vest 100% on January 31, 2025, but may not be converted, redeemed, sold or otherwise transferred for one additional year thereafter. Vesting will be accelerated in the event of a change in control, termination of employment by BXP without cause, or termination of employment by the award recipient for good reason, death, disability or retirement. If there is a change of control prior to January 31, 2025, earned awards will be calculated based on TSR performance up to the date of the change of control. The 2022 MYLTIP awards are in the form of LTIP Units issued on the grant date, and they are subject to forfeiture to the extent awards are not earned. Prior to the performance measurement date holders of the 2022 MYLTIP Units are only entitled to one-tenth (10%) of the regular quarterly distributions payable on common partnership units. Following the completion of the three-year performance period, the Company will also make a “catch-up” cash payment on the 2022 MYLTIP Units that are ultimately earned in an amount equal to the regular and special distributions, if any, declared during the performance period on BXP’s Common Stock, less the distributions actually paid to holders of 2022 MYLTIP Units during the performance period on all of the awarded 2022 MYLTIP Units. Under ASC 718 “Compensation - Stock Compensation,” the 2022 MYLTIP awards have an aggregate value of approximately $17.3 million, which amount will generally be amortized into earnings under the graded vesting method.

On February 4, 2022, the measurement period for the Company’s 2019 MYLTIP awards ended and, based on BXP’s relative TSR performance, the final payout was determined to be 69.0% of target, or an aggregate of approximately $8.6 million (after giving effect to employee separations). As a result, an aggregate of 144,043 2019 MYLTIP Units that had been previously granted were automatically forfeited.

On February 5, 2021, the measurement period for the Company’s 2018 MYLTIP awards ended and, based on BXP’s relative TSR performance, the final awards were determined to be 29.2% of target, or an aggregate of approximately $4.6 million (after giving effect to employee separations). As a result, an aggregate of 285,925 2018 MYLTIP Units that had been previously granted were automatically forfeited.

On February 6, 2020, the measurement period for the Company’s 2017 MYLTIP awards ended and, based on BXP’s relative TSR performance, the final awards were determined to be 83.8% of target, or an aggregate of approximately $17.6 million (after giving effect to employee separations). As a result, an aggregate of 270,942 2017 MYLTIP Units that had been previously granted were automatically forfeited.

BXP issued 41,818, 57,383 and 29,630 shares of restricted common stock and BPLP issued 280,616, 281,640 and 207,181 LTIP Units to employees and non-employee directors under the 2012 Plan and the 2021 Plan during the years ended December 31, 2022, 2021 and 2020, respectively. BXP did not issue any non-qualified stock options under the 2012 Plan or 2021 Plan during the years ended December 31, 2022, 2021 and 2020. BPLP issued 254,061 2022 MYLTIP Units, 352,021 2021 MYLTIP Units and 203,278 2020 MYLTIP Units to employees

under the 2012 Plan and 2021 Plan during the years ended December 31, 2022, 2021 and 2020, respectively. Employees and non-employee directors paid $0.01 per share of restricted common stock and $0.25 per LTIP Unit and MYLTIP Unit. When issued, LTIP Units are not economically equivalent in value to a share of Common Stock, but over time can increase in value to one-for-one parity with Common Stock if there is sufficient appreciation in the value of the Company’s assets. The aggregate value of the LTIP Units is included in noncontrolling interests in the Consolidated Balance Sheets of BXP and BPLP. A majority of the grants of restricted common stock and LTIP Units to employees vest in four equal annual installments. Restricted common stock is measured at fair value on the date of grant based on the number of shares granted and the closing price of BXP’s Common Stock on the date of grant as quoted on the New York Stock Exchange. Such value is recognized as an expense ratably over the corresponding employee service period. Because the 2012 OPP Units and 2013 - 2022 MYLTIP Units are subject to both a service condition and a market condition, the Company recognizes the related compensation expense under the graded vesting attribution method. Under the graded vesting attribution method, each portion of the award that vests at a different date is accounted for as a separate award and recognized over the period appropriate to that portion so that the compensation cost for each portion should be recognized in full by the time that portion vests. The Company recognizes forfeitures as they occur on its awards of stock-based compensation. Dividends paid on both vested and unvested shares of restricted stock are charged directly to Dividends in Excess of Earnings in BXP’s Consolidated Balance Sheets and Partners’ Capital in BPLP’s Consolidated Balance Sheets. Aggregate stock-based compensation expense associated with restricted stock, LTIP Units and 2017 - 2022 MYLTIP Units was approximately $50.7 million, $49.7 million and $43.0 million for the years ended December 31, 2022, 2021 and 2020, respectively. At December 31, 2022, there was (1) an aggregate of approximately $20.6 million of unrecognized compensation expense related to unvested restricted stock and LTIP Units and (2) an aggregate of approximately $4.9 million of unrecognized compensation expense related to unvested 2020 - 2022 MYLTIP Units that is expected to be recognized over a weighted-average period of approximately 1.9 years.

The shares of restricted stock were valued at approximately $4.7 million ($111.47 per share weighted-average), $5.8 million ($100.60 per share weighted-average) and $4.0 million ($133.81 per share weighted-average) for the years ended December 31, 2022, 2021 and 2020, respectively.

LTIP Units were valued using a Monte Carlo simulation method model in accordance with the provisions of ASC 718. LTIP Units issued during the years ended December 31, 2022, 2021 and 2020 were valued at approximately $28.9 million, $23.8 million and $26.3 million, respectively. The weighted-average per unit fair value of LTIP Unit grants in 2022, 2021 and 2020 was $103.06, $84.43 and $127.14, respectively. The per unit fair value of each LTIP Unit granted in 2022, 2021 and 2020 was estimated on the date of grant using the following assumptions; an expected life of 5.7 years, 5.7 years and 5.7 years, a risk-free interest rate of 1.71%, 0.65% and 1.47% and an expected price volatility of 31.0%, 30.0% and 18.0%, respectively.

There were no non-qualified stock options granted during the years ended December 31, 2022, 2021 and 2020.

A summary of the status of BXP’s stock options as of December 31, 2022, 2021 and 2020 and changes during the years then ended are presented below:


	Shares	Weighted-Average Exercise Price
Outstanding at December 31, 2019	395,353	$	96.37
Exercised	(43,792)	$	91.60
Outstanding at December 31, 2020	351,561	$	96.97
Exercised	(247,920)	$	96.95
Outstanding at December 31, 2021	103,641	$	97.01
Exercised	—	$	—
Outstanding at December 31, 2022	103,641	$	97.01

The following table summarizes information about BXP’s stock options outstanding at December 31, 2022:


Options Outstanding				Options Exercisable
Number Outstanding at 12/31/22	Weighted-Average Remaining Contractual Life	Exercise Price		Number Exercisable at 12/31/22	Exercise Price
54,282	0.3 years	$	95.69	54,282	$	95.69
49,359	0.1 years	$	98.46	49,359	$	98.46

There was no total intrinsic value for the outstanding and exercisable stock options as of December 31, 2022. In addition, BXP had 103,641 and 103,641 options exercisable and vested at a weighted-average exercise price of $97.01 and $97.01 at December 31, 2022 and 2021, respectively.

BXP adopted the 1999 Non-Qualified Employee Stock Purchase Plan (the “Stock Purchase Plan”) to encourage the ownership of Common Stock by eligible employees. The Stock Purchase Plan became effective on January 1, 1999 with an aggregate maximum of 250,000 shares of Common Stock available for issuance. The Stock Purchase Plan provides for eligible employees to purchase on the business day immediately following the end of the biannual purchase periods (i.e., January 1-June 30 and July 1-December 31) shares of Common Stock at a purchase price equal to 85% of the average closing prices of the Common Stock during the last ten business days of the purchase period. BXP issued 9,813, 9,846 and 7,195 shares with the weighted-average purchase price equal to $87.30 per share, $89.73 per share and $90.53 per share under the Stock Purchase Plan during the years ended December 31, 2022, 2021 and 2020, respectively.

Real Estate Schedule of Real Estate Properties (Details) - USD ($)
$ in Thousands

Dec. 31, 2022

Dec. 31, 2021

Real Estate Properties [Line Items]

Land

$ 5,189,811

$ 5,061,169

Right-of-use assets - finance leases

237,510

237,507

Right of use assets - operating leases

167,351

169,778

Land held for future development

^[1]

721,501

560,355

Buildings and improvements

15,820,724

14,291,214

Tenant improvements

3,200,743

2,894,025

Furniture, Fixtures and Equipment

50,310

51,695

Construction in progress

406,574

894,172

Total

25,794,524

24,159,915

Less: accumulated depreciation

(6,298,082)

(5,883,961)

Total real estate

19,496,442

18,275,954

Boston Properties Limited Partnership

Real Estate Properties [Line Items]

Land

5,095,102

4,964,986

Right-of-use assets - finance leases

237,510

237,507

Right of use assets - operating leases

167,351

169,778

Land held for future development

^[1]

721,501

560,355

Buildings and improvements

15,547,919

14,014,010

Tenant improvements

3,200,743

2,894,025

Furniture, Fixtures and Equipment

50,310

51,695

Construction in progress

406,574

894,172

Total

25,427,010

23,786,528

Less: accumulated depreciation

(6,180,474)

(5,772,018)

Total real estate

$ 19,246,536

$ 18,014,510

[1]	Includes pre-development costs.

Unsecured Credit Facility (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Jun. 15, 2021	Dec. 31, 2021
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Date		Jun. 15, 2026
Line of Credit, Additional Borrowing Capacity		$ 500,000
Line of Credit Facility, Interest Rate Description		At BPLP’s option, loans under the 2021 Credit Facility will bear interest at a rate per annum equal to (1) (a) in the case of loans denominated in Dollars, LIBOR, (b) in the case of loans denominated in Euro, EURIBOR, (c) in the case of loans denominated in Canadian Dollars, CDOR, and (d) in the case of loans denominated in Sterling, SONIA, in each case, plus a margin ranging from 70.0 to 140.0 basis points based on BPLP’s credit rating or (2) an alternate base rate equal to the greatest of (a) the Federal Funds rate plus 0.5%, (b) the Administrative Agent’s prime rate, (c) LIBOR for a one-month period plus 1.00%, and (d) 1.00%, in each case, plus a margin ranging from 0 to 40 basis points based on BPLP’s credit rating. The 2021 Credit Facility includes provisions which allow LIBOR Daily Floating Rate to be switched to SOFR.
Line of credit facility, maximum percent for loan advances		65.00%
Line of Credit Facility, Commitment Fee Percentage	0.15%
Debt Instrument, Basis Spread on Variable Rate	0.775%
Debt Instrument, Alternate Basis Spread on Variable Rate	0.00%
Long-term Line of Credit	$ 0		$ 145,000
Maximum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage		0.30%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		1.40%
Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage		0.10%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.70%
2017 Credit Facility, Delayed Draw Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 500,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 1,500,000
Long-term Line of Credit	$ 0		$ 145,000

Investments in Unconsolidated Joint Ventures (Tables)

12 Months Ended

Dec. 31, 2022

Schedule of Equity Method Investments [Line Items]

Investments In Unconsolidated Joint Ventures

The investments in unconsolidated joint ventures consist of the following at December 31, 2022 and December 31, 2021:


					Carrying Value of Investment (1)
Entity	Properties	Nominal % Ownership			December 31, 2022		December 31, 2021
					(in thousands)
Square 407 Limited Partnership	Market Square North	50.00	%		$	(6,198)	$	(1,205)
BP/CRF Metropolitan Square LLC	Metropolitan Square	20.00	%		(37,629)		(15,356)
901 New York, LLC	901 New York Avenue	25.00	%	(2)	(12,493)		(12,597)
WP Project Developer LLC	Wisconsin Place Land and Infrastructure	33.33	%	(3)	31,971		33,732
500 North Capitol Venture LLC	500 North Capitol Street, NW	30.00	%		(9,185)		(7,913)
501 K Street LLC	1001 6th Street	50.00	%	(4)	42,922		42,576
Podium Developer LLC	The Hub on Causeway - Podium	50.00	%		46,839		48,980
Residential Tower Developer LLC	Hub50House	50.00	%		45,414		47,774
Hotel Tower Developer LLC	The Hub on Causeway - Hotel Air Rights	50.00	%		12,366		11,505
Office Tower Developer LLC	100 Causeway Street	50.00	%		59,716		57,687
1265 Main Office JV LLC	1265 Main Street	50.00	%		3,465		3,541
BNY Tower Holdings LLC	Dock 72	50.00	%	(5)	(19,921)		28,412

CA-Colorado Center, LLC	Colorado Center	50.00	%		233,862		231,479
7750 Wisconsin Avenue LLC	7750 Wisconsin Avenue	50.00	%		52,152		61,626
BP-M 3HB Venture LLC	3 Hudson Boulevard	25.00	%		116,397		116,306
SMBP Venture LP	Santa Monica Business Park	55.00	%		164,735		156,639
Platform 16 Holdings LP	Platform 16	55.00	%	(6)	158,109		109,086
Gateway Portfolio Holdings LLC	Gateway Commons	50.00	%	(7)	324,038		327,148
Rosecrans-Sepulveda Partners 4, LLC	Beach Cities Media Campus	50.00	%		27,000		27,106
Safeco Plaza REIT LLC	Safeco Plaza	33.67	%	(8)	69,785		72,545
360 PAS Holdco LLC	360 Park Avenue South	42.21	%	(9)	114,992		106,855
PR II/BXP Reston Gateway LLC	Reston Next Residential	20.00	%	(10)	11,351		N/A
751 Gateway Holdings LLC	751 Gateway	49.00	%	(7)	80,714		N/A
200 Fifth Avenue JV LLC	200 Fifth Avenue	26.69	%		120,083		N/A
					$	1,630,485	$	1,445,926

_______________

(5)This property includes net equity balances from the amenity joint venture.

(6)This entity is a VIE (See Note 2).

(7)On June 16, 2022, in accordance with the Gateway Commons joint venture agreement, 751 Gateway was segregated into a new single-purpose joint venture.

approximately 58% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.

Schedule Of Balance Sheets Of The Unconsolidated Joint Ventures [Text Block]

The combined summarized balance sheets of the Company’s unconsolidated joint ventures are as follows:


	December 31, 2022		December 31, 2021
	(in thousands)
ASSETS
Real estate and development in process, net (1)	$	6,537,554	$	5,579,218
Other assets	756,786		586,470
Total assets	$	7,294,340	$	6,165,688
LIABILITIES AND MEMBERS’/PARTNERS’ EQUITY
Mortgage and notes payable, net	$	4,022,746	$	3,214,961
Other liabilities (2)	716,271		652,135
Members’/Partners’ equity	2,555,323		2,298,592
Total liabilities and members’/partners’ equity	$	7,294,340	$	6,165,688
Company’s share of equity	$	1,238,929	$	1,104,175
Basis differentials (3)	391,556		341,751
Carrying value of the Company’s investments in unconsolidated joint ventures (4)	$	1,630,485	$	1,445,926

_______________


	December 31, 2022		December 31, 2021
Property	(in thousands)
Colorado Center	$	301,820	$	304,776
200 Fifth Avenue	94,497		N/A
Gateway Commons	47,808		51,009
Dock 72	(98,980)		(50,051)

These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

Statements Of Operations Of The Joint Ventures

The combined summarized statements of operations of the Company’s unconsolidated joint ventures are as follows:


	Year ended December 31,
		2022		2021		2020
		(in thousands)
Total revenue (1)		$	512,078	$	383,649	$	319,560
Expenses
Operating		198,632		158,498		144,347
Transaction costs		837		470		1,027
Depreciation and amortization		181,041		147,121		141,853
Total expenses		380,510		306,089		287,227
Other income (expense)
Loss from early extinguishment of debt		(1,327)		—		—
Interest expense		(154,065)		(108,884)		(98,051)
Unrealized gain on derivative instruments		1,681		—		—
Gains on sales of real estate (2)		—		—		11,737
Net loss		$	(22,143)	$	(31,324)	$	(53,981)

Company’s share of net loss		$	(2,551)	$	(10,254)	$	(16,256)
Gain on sale of investment (3)		—		10,257		—
Impairment loss on investment (4)		(50,705)		—		(60,524)
Basis differential (5)		(6,584)		(2,573)		(8,330)
Loss from unconsolidated joint ventures		$	(59,840)	$	(2,570)	$	(85,110)

_______________

(1)Includes straight-line rent adjustments of approximately $62.9 million, $17.2 million and $(10.1) million for the years ended December 31, 2022, 2021 and 2020, respectively.

Segment Information (Tables)

12 Months Ended

Dec. 31, 2022

Segment Reporting [Abstract]

Schedule Of Reconciliation Of Net Operating Income To Net Income

BXP


	Year ended December 31,
		2022		2021		2020
		(in thousands)
Net income attributable to Boston Properties, Inc. common shareholders		$	848,947	$	496,223	$	862,227
Add:
Preferred stock redemption charge		—		6,412		—
Preferred dividends		—		2,560		10,500
Noncontrolling interest—common units of the Operating Partnership		96,780		55,931		97,704
Noncontrolling interests in property partnerships		74,857		70,806		48,260
Interest expense		437,139		423,346		431,717
Losses from early extinguishment of debt		—		45,182		—
Unrealized loss on non-real estate investment		150		—		—
Net operating income from unconsolidated joint ventures		146,081		107,756		94,943
Loss from unconsolidated joint ventures		59,840		2,570		85,110
Depreciation and amortization expense		749,775		717,336		683,751
Transaction costs		2,905		5,036		1,531
Payroll and related costs from management services contracts		15,450		12,487		11,626
General and administrative expense		146,378		151,573		133,112
Less:
Net operating income attributable to noncontrolling interests in property partnerships		191,812		186,304		162,887
Gains (losses) from investments in securities		(6,453)		5,626		5,261
Other income - assignment fee		6,624		—		—
Interest and other income (loss)		11,940		5,704		5,953
Gain on sales-type lease		10,058		—		—
Gains on sales of real estate		437,019		123,660		618,982
Direct reimbursements of payroll and related costs from management services contracts		15,450		12,487		11,626
Development and management services revenue		28,056		27,697		29,641
Company’s share of Net Operating Income		$	1,883,796	$	1,735,740	$	1,626,131

BPLP


	Year ended December 31,
		2022		2021		2020
		(in thousands)
Net income attributable to Boston Properties Limited Partnership common unitholders		$	957,265	$	561,993	$	979,979
Add:
Preferred unit redemption charge		—		6,412		—
Preferred distributions		—		2,560		10,500
Noncontrolling interests in property partnerships		74,857		70,806		48,260
Interest expense		437,139		423,346		431,717
Losses from early extinguishment of debt		—		45,182		—
Unrealized loss on non-real estate investment		150		—		—
Net operating income from unconsolidated joint ventures		146,081		107,756		94,943
Loss from unconsolidated joint ventures		59,840		2,570		85,110
Depreciation and amortization expense		742,293		709,035		676,666
Transaction costs		2,905		5,036		1,531
Payroll and related costs from management services contracts		15,450		12,487		11,626
General and administrative expense		146,378		151,573		133,112
Less:
Net operating income attributable to noncontrolling interests in property partnerships		191,812		186,304		162,887
Gains (losses) from investments in securities		(6,453)		5,626		5,261
Other income - assignment fee		6,624		—		—
Interest and other income (loss)		11,940		5,704		5,953
Gain on sales-type lease		10,058		—		—
Gains on sales of real estate		441,075		125,198		631,945
Direct reimbursements of payroll and related costs from management services contracts		15,450		12,487		11,626
Development and management services revenue		28,056		27,697		29,641
Company’s share of Net Operating Income		$	1,883,796	$	1,735,740	$	1,626,131

Schedule Of Segment Information By Geographic Area And Property Type

Information by geographic area and property type (dollars in thousands):

For the year ended December 31, 2022:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Premier Workplace	$	1,005,156		$	—		$	1,031,479		$	534,397		$	31,978		$	365,402		$	2,968,412
Residential	15,086			—			—			14,769			—			27,326			57,181
Hotel	39,482			—			—			—			—			—			39,482
Total	1,059,724			—			1,031,479			549,166			31,978			392,728			3,065,075
% of Grand Totals	34.58		%	—		%	33.65		%	17.92		%	1.04		%	12.81		%	100.00		%
Rental Expenses:
Premier Workplace	360,218			—			391,293			183,353			8,386			135,237			1,078,487
Residential	5,961			—			—			11,371			—			12,251			29,583
Hotel	27,478			—			—			—			—			—			27,478
Total	393,657			—			391,293			194,724			8,386			147,488			1,135,548
% of Grand Totals	34.66		%	—		%	34.46		%	17.15		%	0.74		%	12.99		%	100.00		%
Net operating income	$	666,067		$	—		$	640,186		$	354,442		$	23,592		$	245,240		$	1,929,527
% of Grand Totals	34.52		%	—		%	33.18		%	18.37		%	1.22		%	12.71		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(45,822)			—			(145,990)			—			—			—			(191,812)
Add: Company’s share of net operating income (loss) from unconsolidated joint ventures	34,233			53,023			1,594			12,785			7,690			36,756			146,081
Company’s share of net operating income	$	654,478		$	53,023		$	495,790		$	367,227		$	31,282		$	281,996		$	1,883,796
% of Grand Totals	34.75		%	2.81		%	26.32		%	19.49		%	1.66		%	14.97		%	100.00		%

_______________

(1)Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

For the year ended December 31, 2021:


	Boston			Los Angeles			New York			San Francisco			Seattle				Washington, DC			Total
Rental Revenue: (1)
Premier Workplace	$	930,560		$	—		$	1,012,172		$	508,620		$	—			$	340,808		$	2,792,160
Residential	13,397			—			—			3,892			—				25,379			42,668
Hotel	13,609			—			—			—			—				—			13,609
Total	957,566			—			1,012,172			512,512			—				366,187			2,848,437
% of Grand Totals	33.62		%	—		%	35.53		%	17.99		%	—		%		12.86		%	100.00		%
Rental Expenses:
Premier Workplace	322,298			—			379,267			168,040			—				127,102			996,707
Residential	5,811			—			—			6,717			—				11,916			24,444
Hotel	12,998			—			—			—			—				—			12,998
Total	341,107			—			379,267			174,757			—			—	139,018			1,034,149
% of Grand Totals	32.98		%	—		%	36.67		%	16.90		%	—		%		13.45		%	100.00		%
Net operating income	$	616,459		$	—		$	632,905		$	337,755		$	—			$	227,169		$	1,814,288
% of Grand Totals	33.98		%	—		%	34.88		%	18.62		%	—		%		12.52		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(43,232)			—			(143,072)			—			—				—			(186,304)
Add: Company’s share of net operating income (loss) from unconsolidated joint ventures	16,551			51,641			(664)			14,152			2,498				23,578			107,756
Company’s share of net operating income	$	589,778		$	51,641		$	489,169		$	351,907		$	2,498			$	250,747		$	1,735,740
% of Grand Totals	33.98		%	2.98		%	28.18		%	20.27		%	0.14		%		14.45		%	100.00		%

_______________

For the year ended December 31, 2020:


	Boston			Los Angeles			New York			San Francisco			Washington, DC			Total
Rental Revenue: (1)
Premier Workplace	$	897,915		$	—		$	935,966		$	508,327		$	336,587		$	2,678,795
Residential	13,616			—			—			155			24,375			38,146
Hotel	7,478			—			—			—			—			7,478
Total	919,009			—			935,966			508,482			360,962			2,724,419
% of Grand Totals	33.73		%	—		%	34.36		%	18.66		%	13.25		%	100.00		%
Rental Expenses:
Premier Workplace	318,509			—			384,753			163,156			132,051			998,469
Residential	5,378			—			—			2,261			11,100			18,739
Hotel	13,136			—			—			—			—			13,136
Total	337,023			—			384,753			165,417			143,151			1,030,344
% of Grand Totals	32.71		%	—		%	37.35		%	16.05		%	13.89		%	100.00		%
Net operating income	$	581,986		$	—		$	551,213		$	343,065		$	217,811		$	1,694,075
% of Grand Totals	34.35		%	—		%	32.54		%	20.25		%	12.86		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(41,849)			—			(121,038)			—			—			(162,887)
Add: Company’s share of net operating income from unconsolidated joint ventures	10,765			57,907			(5,326)			14,928			16,669			94,943
Company’s share of net operating income	$	550,902		$	57,907		$	424,849		$	357,993		$	234,480		$	1,626,131
% of Grand Totals	33.88		%	3.56		%	26.12		%	22.02		%	14.42		%	100.00		%

_______________

Stock Option Rollforward Table (Details) - $ / shares	12 Months Ended
Stock Option Rollforward Table (Details) - $ / shares	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Text Block [Abstract]
Beginning outstanding, shares	103,641	351,561	395,353
Exercised	0	(247,920)	(43,792)
Ending outstanding, shares	103,641	103,641	351,561
Beginning outstanding, Weighted-average Exercise Price	$ 97.01	$ 96.97	$ 96.37
Weighted Average Exercise Price	0	96.95	91.60
Ending outstanding, Weighted-average Exercise Price	$ 97.01	$ 97.01	$ 96.97

Stock Option and Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2022

Text Block [Abstract]

Share-based Payment Arrangement, Option, Activity

A summary of the status of BXP’s stock options as of December 31, 2022, 2021 and 2020 and changes during the years then ended are presented below:


	Shares	Weighted-Average Exercise Price
Outstanding at December 31, 2019	395,353	$	96.37
Exercised	(43,792)	$	91.60
Outstanding at December 31, 2020	351,561	$	96.97
Exercised	(247,920)	$	96.95
Outstanding at December 31, 2021	103,641	$	97.01
Exercised	—	$	—
Outstanding at December 31, 2022	103,641	$	97.01

Schedule of Stock Options Outstanding

The following table summarizes information about BXP’s stock options outstanding at December 31, 2022:


Options Outstanding				Options Exercisable
Number Outstanding at 12/31/22	Weighted-Average Remaining Contractual Life	Exercise Price		Number Exercisable at 12/31/22	Exercise Price
54,282	0.3 years	$	95.69	54,282	$	95.69
49,359	0.1 years	$	98.46	49,359	$	98.46

Noncontrolling Interests

12 Months Ended

Dec. 31, 2022

Noncontrolling Interest [Abstract]

Noncontrolling Interests

9. Noncontrolling Interests

Noncontrolling interests relate to the interests in BPLP not owned by BXP and interests in consolidated property partnerships not wholly-owned by the Company. As of December 31, 2022, the noncontrolling interests in BPLP consisted of 16,531,172 OP Units, 1,679,175 LTIP Units (including 464,036 LTIP Units earned by employees under the Company’s multi-year long-term incentive awards granted between 2012 and 2019 (i.e., 2012 OPP and 2013 - 2019 MYLTIP awards)), 203,278 2020 MYLTIP Units, 350,989 2021 MYLTIP Units and 253,453 2022 MYLTIP Units held by parties other than BXP.

Noncontrolling Interest—Common Units

During the years ended December 31, 2022 and 2021, 182,929 and 523,969 OP Units, respectively, were presented by the holders for redemption (including 78,249 and 148,442 OP Units, respectively, issued upon conversion of LTIP Units, 2012 OPP Units and MYLTIP Units) and were redeemed by BXP in exchange for an equal number of shares of Common Stock.

At December 31, 2022, BPLP had outstanding 203,278 2020 MYLTIP Units, 350,989 2021 MYLTIP Units and 253,453 2022 MYLTIP Units. Prior to the end of the respective three-year performance period for each plan, holders of MYLTIP Units are entitled to receive per unit distributions equal to one-tenth (10%) of the regular quarterly distributions payable on an OP Unit, but will not be entitled to receive any special distributions. After the three-year performance period for each plan has ended, (1) the number of MYLTIP Units, both vested and unvested, that MYLTIP award recipients have earned, if any, based on the establishment of a performance pool, will be entitled to receive distributions in an amount per unit equal to distributions, both regular and special, payable on an OP Unit and (2) with respect to the 2021 MYLTIP and 2022 MYLTIP only, the Company will make a “catch-up” cash payment on the MYLTIP Units that are ultimately earned in an amount equal to the regular and special dividends, if any, declared during the performance period on Common Stock, less the distributions actually paid during the performance period on all of the awarded 2021 MYLTIP Units and 2022 MYLTIP Units.

On February 6, 2020, the measurement period for the Company’s 2017 MYLTIP awards ended and, based on BXP’s relative total stockholder return (“TSR”) performance, the final awards were determined to be 83.8% of target, or an aggregate of approximately $17.6 million (after giving effect to employee separations). As a result, an aggregate of 270,942 2017 MYLTIP Units that had been previously granted were automatically forfeited.

On December 14, 2021, BPLP issued approximately 866,503 OP Units as partial consideration for the acquisition of 360 Park Avenue South in New York, New York. The OP Units issued totaled approximately $99.7 million based on the average closing price per share of BXP’s common stock for the five trading days immediately preceding the closing date.

The following table presents BPLP’s distributions on the OP Units and LTIP Units (including the 2012 OPP Units, 2013 - 2018 MYLTIP Units and, after the February 4, 2022 measurement date, the 2019 MYLTIP Units) and its distributions on the 2019 MYLTIP Units (prior to the February 4, 2022 measurement date) and 2020 - 2022 MYLTIP Units (after the February 1, 2022 issuance date of the 2022 MYLTIP Units) that occurred during the year ended December 31, 2022:


Record Date	Payment Date	Distributions per OP Unit and LTIP Unit	Distributions per MYLTIP Unit
December 30, 2022	January 30, 2023	$0.98	$0.098
September 30, 2022	October 31, 2022	$0.98	$0.098
June 30, 2022	July 29, 2022	$0.98	$0.098
March 31, 2022	April 29, 2022	$0.98	$0.098
December 31, 2021	January 28, 2022	$0.98	$0.098

The following table presents BPLP’s distributions on the OP Units and LTIP Units (including the 2012 OPP Units, 2013 - 2017 MYLTIP Units and, after the February 5, 2021 measurement date, the 2018 MYLTIP Units) and its distributions on the 2018 MYLTIP Units (prior to the February 5, 2021 measurement date) and 2019 - 2021 MYLTIP Units (after the February 2, 2021 issuance date of the 2021 MYLTIP Units) that occurred during the year ended December 31, 2021:


Record Date	Payment Date	Distributions per OP Unit and LTIP Unit	Distributions per MYLTIP Unit
December 31, 2021	January 28, 2022	$0.98	$0.098
September 30, 2021	October 29, 2021	$0.98	$0.098
June 30, 2021	July 30, 2021	$0.98	$0.098
March 31, 2021	April 30, 2021	$0.98	$0.098
December 31, 2020	January 28, 2021	$0.98	$0.098

The following table presents BPLP’s distributions on the OP Units and LTIP Units (including the 2012 OPP Units, 2013 - 2016 MYLTIP Units and, after the February 6, 2020 measurement date, the 2017 MYLTIP Units) and its distributions on the 2017 MYLTIP Units (prior to the February 6, 2020 measurement date) and 2018 - 2020 MYLTIP Units (after the February 4, 2020 issuance date of the 2020 MYLTIP Units) that occurred during the year ended December 31, 2020:


Record Date	Payment Date	Distributions per OP Unit and LTIP Unit	Distributions per MYLTIP Unit
December 31, 2020	January 28, 2021	$0.98	$0.098
September 30, 2020	October 30, 2020	$0.98	$0.098
June 30, 2020	July 31, 2020	$0.98	$0.098
March 31, 2020	April 30, 2020	$0.98	$0.098
December 31, 2019	January 30, 2020	$0.98	$0.098

A holder of an OP Unit may present the OP Unit to BPLP for redemption at any time (subject to restrictions agreed upon at the time of issuance of OP Units to particular holders that may restrict such redemption right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, BPLP must redeem the OP Unit for cash equal to the then value of a share of Common Stock of BXP. BXP may, in its sole discretion, elect to assume and satisfy the redemption obligation by paying either cash or issuing one share of Common Stock. The value of the OP Units (other than OP Units owned by BXP), and LTIP Units (including the 2012 OPP Units and 2013 - 2019 MYLTIP Units), assuming in each case that all conditions had been met for the conversion thereof, had all of such units been redeemed at December 31, 2022 was approximately $1.3 billion based on the last reported price of a share of Common Stock on the New York Stock Exchange of $67.58 per share on December 30, 2022.

Noncontrolling Interests—Property Partnerships

The noncontrolling interests in property partnerships consist of the outside equity interests in ventures that are consolidated with the financial results of the Company because the Company exercises control over the entities that own the properties. The equity interests in these ventures that are not owned by the Company, totaling approximately $1.5 billion and $1.6 billion at December 31, 2022 and December 31, 2021, respectively, are included in Noncontrolling Interests—Property Partnerships on the accompanying Consolidated Balance Sheets.

Organization	12 Months Ended
Organization	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization BXP is a fully integrated, self-administered and self-managed REIT. BXP is the sole general partner of BPLP, its operating partnership, and at December 31, 2022 owned an approximate 89.6% (89.7% at December 31, 2021) general and limited partnership interest in BPLP. Unless stated otherwise or the context requires, the “Company” refers to BXP and its subsidiaries, including BPLP and its consolidated subsidiaries. Partnership interests in BPLP include: •common units of partnership interest (also referred to as “OP Units”) and •long term incentive units of partnership interest (also referred to as “LTIP Units”) Unless specifically noted otherwise, all references to OP Units exclude units held by BXP. A holder of an OP Unit may present the OP Unit to BPLP for redemption at any time (subject to restrictions agreed upon at the time of issuance of OP Units to particular holders that may restrict such redemption right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, BPLP is obligated to redeem the OP Unit for cash equal to the value of a share of common stock of BXP (“Common Stock”). In lieu of such cash redemption, BXP may elect to acquire the OP Unit for one share of Common Stock. Because the number of shares of Common Stock outstanding at all times equals the number of OP Units that BXP owns, one share of Common Stock is generally the economic equivalent of one OP Unit, and the quarterly distribution that may be paid to the holder of an OP Unit equals the quarterly dividend that may be paid to the holder of a share of Common Stock. The Company uses LTIP Units as a form of time-based, restricted equity compensation and as a form of performance-based equity compensation for employees, and has previously granted LTIP Units in the form of (1) 2012 outperformance plan awards (“2012 OPP Units”) and (2) 2013 - 2022 multi-year, long-term incentive program awards (also referred to as “MYLTIP Units”), each of which, upon the satisfaction of certain performance-based and time-based vesting conditions, is convertible into one OP Unit. The three-year measurement periods for the 2012 OPP Units and the 2013 - 2019 MYLTIP Units have ended and BXP’s total stockholder return (“TSR”) was sufficient for employees to earn and therefore become eligible to vest in a portion of the awards. Unless and until they are earned, the rights, preferences and privileges of the 2020 - 2022 MYLTIP Units differ from other LTIP Units granted to employees (including the 2012 OPP Units and the 2013 - 2019 MYLTIP Units, which have been earned). Therefore, unless specifically noted otherwise, all references to LTIP Units exclude the 2020 - 2022 MYLTIP Units. LTIP Units (including the earned 2012 OPP Units and the earned 2013 - 2019 MYLTIP Units), whether vested or not, will receive the same quarterly per unit distributions as OP Units, which equal per share dividends on Common Stock (See Notes 9, 14 and 16). Properties At December 31, 2022, the Company owned or had joint venture interests in a portfolio of 194 commercial real estate properties (the “Properties”) aggregating approximately 54.1 million net rentable square feet of primarily premier workplaces, including 13 properties under construction/redevelopment totaling approximately 3.2 million net rentable square feet. At December 31, 2022, the Properties consisted of: •173 office and life sciences properties (including 10 properties under construction/redevelopment); •14 retail properties (including two properties under construction/redevelopment); •six residential properties (including one property under construction); and •one hotel. The Company considers premier workplaces to be well-located buildings that are modern structures or have been modernized to compete with newer buildings and professionally managed and maintained. As such, these properties attract high-quality tenants and command upper-tier rental rates. All references to acres and square footage in the Notes are unaudited. Basis of Presentation The accompanying consolidated financial statements are presented using the accrual basis of accounting in conformity with accounting principles generally accepted in the United States of America. BXP does not have any other significant assets, liabilities or operations, other than its investment in BPLP, nor does it have employees of its own. BPLP, not BXP, generally executes all significant business relationships other than transactions involving securities of BXP. All majority-owned subsidiaries and joint ventures over which the Company has financial and operating control and variable interest entities (“VIEs”) in which the Company has determined it is the primary beneficiary are included in the consolidated financial statements. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for all other unconsolidated joint ventures using the equity method of accounting. Accordingly, the Company’s share of the earnings of these joint ventures and companies is included in consolidated net income. Variable Interest Entities (VIEs) Consolidated VIEs are those for which the Company is considered to be the primary beneficiary of a VIE. The primary beneficiary is the entity that has a controlling financial interest in the VIE, which is defined by the entity having both of the following characteristics: (1) the power to direct the activities that, when taken together, most significantly impact the VIE’s performance and (2) the obligation to absorb losses or the right to receive the returns from the VIE that could potentially be significant to the VIE. The assets of each VIE are only available to satisfy such VIE's respective liabilities. The Company has determined that it is the primary beneficiary for six of the seven entities that are VIEs as of December 31, 2022. Consolidated Variable Interest Entities As of December 31, 2022, BXP has identified six consolidated VIEs, including BPLP. Excluding BPLP, the VIEs consisted of the following five in-service properties: 767 Fifth Avenue (the General Motors Building), Times Square Tower, 601 Lexington Avenue, Atlantic Wharf Office Building and 100 Federal Street. The Company consolidates these VIEs because it is the primary beneficiary. The third parties’ interests in these consolidated entities (excluding BPLP’s interest) are reflected as noncontrolling interests in property partnerships in the accompanying consolidated financial statements (See Note 9). In addition, BXP’s only significant asset is its investment in BPLP and, consequently, substantially all of BXP’s assets and liabilities are the assets and liabilities of BPLP. Variable Interest Entities Not Consolidated As of December 31, 2022, the Company has determined that the Platform 16 Holdings LP joint venture is a VIE. The Company does not consolidate this entity as the Company does not have the power to direct the activities that, when taken together, most significantly impact the VIE’s performance and, therefore, the Company is not considered to be the primary beneficiary.

Commitments And Contingencies	12 Months Ended
Commitments And Contingencies	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	8. Commitments and Contingencies General In the normal course of business, the Company guarantees its performance of services or indemnifies third parties against its negligence. In addition, in the normal course of business, the Company guarantees to certain tenants the obligations of its subsidiaries for the payment of tenant improvement allowances and brokerage commissions in connection with their leases and limited costs arising from delays in delivery of their premises. The Company had letter of credit and performance obligations related to lender and development requirements that total approximately $26.5 million at December 31, 2022. Certain of the Company’s joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of its interest in the joint ventures. From time to time, under certain of the Company’s joint venture agreements, if certain return thresholds are achieved, either the Company or its partners may be entitled to an additional promoted interest or payments. From time to time, the Company (or ventures in which the Company has an ownership interest) has agreed, and may in the future agree, to (1) guarantee portions of the principal, interest and other amounts in connection with their borrowings, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) in connection with their borrowings and (3) provide guarantees to lenders, tenants and other third parties for the completion of development projects. The Company has agreements with its outside or joint venture partners whereby the partners agree to reimburse the joint venture for their share of any payments made under the guarantee. In some cases, the Company earns a fee from the applicable joint venture for providing the guarantee. In connection with the refinancing of 767 Fifth Avenue’s (the General Motors Building) secured loan by the Company’s consolidated joint venture entity, 767 Venture, LLC, the Company guaranteed the consolidated entity’s obligation to fund various reserves for tenant improvement costs and allowances, leasing commissions and free rent obligations in lieu of cash deposits. As of December 31, 2022, the maximum funding obligation under the guarantee was approximately $13.7 million. The Company earns a fee from the joint venture for providing the guarantee and has an agreement with the outside partners to reimburse the joint venture for their share of any payments made under the guarantee. As of December 31, 2022, no amounts related to the guarantee were recorded as liabilities in the Company’s consolidated financial statements. In connection with the development of the 7750 Wisconsin Avenue office property located in Bethesda, Maryland, the Company entered into agreements with affiliates of The Bernstein Companies (the Company’s partner in the 7750 Wisconsin Avenue joint venture) under which the Company could be required to act as a mezzanine and/or mortgage lender and finance the construction of the hotel property being developed by an affiliate of The Bernstein Companies adjacent to the office property. An affiliate of The Bernstein Companies exercised its option to borrow $10.0 million from the Company under such agreements, and the Company provided the financing on June 1, 2020. The financing bore interest at a fixed rate of 8.00% per annum, compounded monthly, and was scheduled to mature on the fifth anniversary of the date on which the base building of the affiliate of The Bernstein Companies’ hotel property was substantially completed. On June 27, 2022, the borrower repaid the loan in full, including approximately $1.6 million of accrued interest. The financing was recorded as Note Receivable, Net in the Company’s Consolidated Balance Sheets. In connection with the redevelopment of the Company’s 325 Main Street property located in Cambridge, Massachusetts, the Company was required pursuant to the local zoning ordinance and urban renewal plan to commence construction of a residential building of at least 200,000 square feet with 25% of the project designated as income-restricted (with a minimum of 20% of the square footage devoted to home ownership units) prior to the occupancy of the 325 Main Street property. Each of the zoning ordinance and urban renewal plan was amended to decouple the residential requirement from the occupancy of the 325 Main Street property. 325 Main Street consisted of an approximately 115,000 net rentable square foot premier workplace that was demolished and redeveloped into an approximately 414,000 net rentable square foot premier workplace. While the amendment to the urban renewal plan is subject to completion of administrative processes, the City of Cambridge issued a temporary certificate of occupancy in the second quarter of 2022 (See Note 3). Concentrations of Credit Risk Management of the Company performs ongoing credit evaluations of tenants and may require tenants to provide some form of credit support such as corporate guarantees and/or other financial guarantees. Although the Company’s properties are geographically diverse and tenants operate in a variety of industries, to the extent the Company has a significant concentration of rental revenue from any single tenant, the inability of that tenant to make its lease payments could have an adverse effect on the Company. Insurance The Company’s property insurance program per occurrence limits are $1.0 billion for its portfolio insurance program, including coverage for acts of terrorism other than nuclear, biological, chemical or radiological terrorism (“Terrorism Coverage”). The Company also carries $1.35 billion of property insurance in excess of the $1.0 billion of coverage in the Company’s property insurance program for 601 Lexington Avenue, New York, New York, consisting of $750 million of property and Terrorism Coverage in excess of the Company’s property insurance program and $600 million of Terrorism Coverage only in excess of the $1.75 billion of coverage. Certain properties, including the General Motors Building located at 767 Fifth Avenue in New York, New York (“767 Fifth Avenue”), are currently insured in separate insurance programs. The property insurance program per occurrence limits for 767 Fifth Avenue are $1.625 billion, including Terrorism Coverage. The Company also currently carries nuclear, biological, chemical and radiological terrorism insurance coverage for acts of terrorism certified under the Federal Terrorism Risk Insurance Act (as amended, “TRIA”) (“NBCR Coverage”), which is provided by IXP as a direct insurer, for the properties in the Company’s portfolio, including 767 Fifth Avenue, but excluding certain other properties owned in joint ventures with third parties or which the Company manages. The per occurrence limit for NBCR Coverage is $1.0 billion. Under TRIA, after the payment of the required deductible and coinsurance, the NBCR Coverage provided by IXP is backstopped by the Federal Government if the aggregate industry insured losses resulting from a certified act of terrorism exceed a “program trigger.” The program trigger is $200 million, the coinsurance is 20% and the deductible is 20% of the premiums earned by the insurer for the year prior to a claim. If the Federal Government pays out for a loss under TRIA, it is mandatory that the Federal Government recoup the full amount of the loss from insurers offering TRIA coverage after the payment of the loss pursuant to a formula in TRIA. The Company may elect to terminate the NBCR Coverage if the Federal Government seeks recoupment for losses paid under TRIA, if TRIA is not extended after its expiration on December 31, 2027, if there is a change in its portfolio or for any other reason. The Company intends to continue to monitor the scope, nature and cost of available terrorism insurance. The Company also currently carries earthquake insurance on its properties located in areas known to be subject to earthquakes. Specifically, the Company currently carries earthquake insurance which covers its San Francisco and Los Angeles regions with a $330 million per occurrence limit, and a $330 million annual aggregate limit, $30 million of which is provided by IXP, as a direct insurer. This insurance is subject to a deductible in the amount of 3% of the value of the affected property. In addition, the Company currently carries earthquake insurance which covers its Seattle region with a $110 million per occurrence limit, and a $110 million annual aggregate limit. This insurance is subject to a deductible in the amount of 2% of the value of the affected property. The amount of the Company’s earthquake insurance coverage may not be sufficient to cover losses from earthquakes. In addition, the amount of earthquake coverage could impact the Company’s ability to finance properties subject to earthquake risk. The Company may discontinue earthquake insurance or change the structure of its earthquake insurance program on some or all of its properties in the future if the premiums exceed the Company’s estimation of the value of the coverage. IXP, a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s earthquake insurance coverage for its Greater San Francisco and Los Angeles properties and the Company’s NBCR Coverage. Insofar as the Company owns IXP, it is responsible for its liquidity and capital resources, and the accounts of IXP are part of the Company’s consolidated financial statements. In particular, if a loss occurs which is covered by the Company’s NBCR Coverage but is less than the applicable program trigger under TRIA, IXP would be responsible for the full amount of the loss without any backstop by the Federal Government. IXP would also be responsible for any recoupment charges by the Federal Government in the event losses are paid out and its insurance policy is maintained after the payout by the Federal Government. If the Company experiences a loss and IXP is required to pay under its insurance policy, the Company would ultimately record the loss to the extent of the required payment. Therefore, insurance coverage provided by IXP should not be considered as the equivalent of third-party insurance, but rather as a modified form of self-insurance. In addition, BPLP has issued a guarantee to cover liabilities of IXP in the amount of $20.0 million. The Company continues to monitor the state of the insurance market in general, and the scope and costs of coverage for acts of terrorism, earthquakes and pandemics, in particular, but the Company cannot anticipate what coverage will be available on commercially reasonable terms in future policy years. There are other types of losses, such as from wars, for which the Company cannot obtain insurance at all or at a reasonable cost. With respect to such losses and losses from acts of terrorism, earthquakes, pandemics or other catastrophic events, if the Company experiences a loss that is uninsured or that exceeds policy limits, the Company could lose the capital invested in the damaged properties, as well as the anticipated future revenues from those properties. Depending on the specific circumstances of each affected property, it is possible that the Company could be liable for mortgage indebtedness or other obligations related to the property. Any such loss could materially and adversely affect the Company’s business and financial condition and results of operations. Legal Matters The Company is subject to various legal proceedings and claims that arise in the ordinary course of business. These matters are generally covered by insurance. Management believes that the final outcome of such matters will not have a material adverse effect on the financial position, results of operations or liquidity of the Company. State and Local Tax Matters Because BXP is organized and qualifies as a REIT, it is generally not subject to federal income taxes, but is subject to certain state and local taxes. In the normal course of business, certain entities through which the Company owns real estate either have undergone, or are currently undergoing, tax audits. Although the Company believes that it has substantial arguments in favor of its positions in the ongoing audits, in some instances there is no controlling precedent or interpretive guidance on the specific point at issue. Collectively, tax deficiency notices received to date from the jurisdictions conducting the ongoing audits have not been material. However, there can be no assurance that future audits will not occur with increased frequency or that the ultimate result of such audits will not have a material adverse effect on the Company’s results of operations. Environmental Matters It is the Company’s policy to retain independent environmental consultants to conduct or update Phase I environmental assessments (which generally do not involve invasive techniques such as soil or ground water sampling) and asbestos surveys in connection with the Company’s acquisition of properties. These pre-purchase environmental assessments have not revealed environmental conditions that the Company believes will have a material adverse effect on its business, assets, financial condition, results of operations or liquidity, and the Company is not otherwise aware of environmental conditions with respect to its properties that the Company believes would have such a material adverse effect. However, from time to time environmental conditions at the Company’s properties have required and may in the future require environmental testing and/or regulatory filings, as well as remedial action. In February 1999, the Company (through a joint venture) acquired from Exxon Corporation a property in Massachusetts that was formerly used as a petroleum bulk storage and distribution facility and was known by the state regulatory authority to contain soil and groundwater contamination. The Company developed an office park on the property. The Company engaged a specially licensed environmental consultant to oversee the management of contaminated soil and groundwater that was disturbed in the course of construction. Under the property acquisition agreement, Exxon agreed to (1) bear the liability arising from releases or discharges of oil and hazardous substances which occurred at the site prior to the Company’s ownership, (2) continue monitoring and/or remediating such releases and discharges as necessary and appropriate to comply with applicable requirements, and (3) indemnify the Company for certain losses arising from preexisting site conditions. Any indemnity claim may be subject to various defenses and contractual limitations, including time limits, and there can be no assurance that the amounts paid under the indemnity, if any, would be sufficient to cover the liabilities arising from any such releases and discharges. Environmental investigations at some of the Company’s properties and certain properties owned by affiliates of the Company have identified groundwater contamination migrating from off-site source properties. In each case the Company engaged a licensed environmental consultant to perform the necessary investigations and assessments and to prepare any required submittals to the regulatory authorities. In each case the environmental consultant concluded that the properties qualify under the regulatory program or the regulatory practice for a status which eliminates certain deadlines for conducting response actions at a site. The Company also believes that these properties qualify for liability relief under certain statutory provisions or regulatory practices regarding upgradient releases. Although the Company believes that the current or former owners of the upgradient source properties may bear responsibility for some or all of the costs of addressing the identified groundwater contamination, the Company will take such further response actions (if any) that it deems necessary or advisable. Other than periodic testing at some of these properties, no such additional response actions are anticipated at this time. Some of the Company’s properties and certain properties owned by the Company’s affiliates are located in urban, industrial and other previously developed areas where fill or current or historical uses of the areas have caused site contamination. Accordingly, it is sometimes necessary to institute special soil and/or groundwater handling procedures and/or include particular building design features in connection with development, construction and other property operations in order to achieve regulatory closure and/or ensure that contaminated materials are addressed in an appropriate manner. In these situations, it is the Company’s practice to investigate the nature and extent of detected contamination, including potential issues associated with vapor intrusion concerns and/or potential contaminant migration to or from the subject property in ground water, assess potential liability risks and estimate the costs of required response actions and special handling procedures. The Company then uses this information as part of its decision-making process with respect to the acquisition, deal structure and/or development of the property. For example, the Company owns a parcel in Massachusetts which was formerly used as a quarry/asphalt batching facility. Pre-purchase testing indicated that the site contained relatively low levels of certain contaminants. The Company has developed an office park on this property. Prior to and during redevelopment activities, the Company engaged a specially licensed environmental consultant to monitor environmental conditions at the site and prepare necessary regulatory submittals based on the results of an environmental risk characterization. A submittal has been made to the regulatory authorities in order to achieve regulatory closure at this site. The submittal included an environmental deed restriction that mandates compliance with certain protective measures in a portion of the site where low levels of residual soil contamination have been left in place in accordance with applicable laws. The Company expects that resolution of the environmental matters relating to the above will not have a material impact on its business, assets, financial condition, results of operations or liquidity. However, the Company cannot assure you that it has identified all environmental liabilities at its properties, that all necessary remediation actions have been or will be undertaken at the Company’s properties or that the Company will be indemnified, in full or at all or that the Company will have insurance coverage, in the event that such environmental liabilities arise.

Investments in Unconsolidated Joint Ventures (Investments in Unconsolidated Joint Ventures) (Details)
$ in Thousands

12 Months Ended

Dec. 31, 2022

USD ($)

ft²

payments

Dec. 31, 2021

USD ($)

Schedule of Equity Method Investments [Line Items]

Other Liabilities

$ (450,918)

$ (391,441)

Investments in unconsolidated joint ventures

1,715,911

1,482,997

Investments In Affiliates Subsidiaries Associates And Joint Ventures net

^[1]

1,630,485

1,445,926

Unconsolidated Joint Ventures [Member]

Schedule of Equity Method Investments [Line Items]

Other Liabilities

$ (85,400)

(37,100)

Square 407 Limited Partnership [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Market Square North

Ownership Percentage

50.00%

Other Liabilities

^[1]

$ (6,198)

(1,205)

BP/CRF Metropolitan Square LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Metropolitan Square

Ownership Percentage

20.00%

Other Liabilities

^[1]

$ (37,629)

(15,356)

901 New York Avenue LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

901 New York Avenue

Ownership Percentage

^[2]

25.00%

Other Liabilities

^[1]

$ (12,493)

$ (12,597)

901 New York Avenue LLC (economic ownership) [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

WP Project Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Wisconsin Place Land and Infrastructure

Ownership Percentage

^[3]

33.33%

Investments in unconsolidated joint ventures

^[1]

$ 31,971

$ 33,732

500 North Capitol Venture LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

500 North Capitol Street, NW

Ownership Percentage

30.00%

Other Liabilities

^[1]

$ (9,185)

(7,913)

501 K Street LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

1001 6th Street

Ownership Percentage

^[4]

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 42,922

42,576

Potential additonal payments to joint venture partner | payments

Minimum square footage to make a potential additional payment to joint venture partner (in sqft) | ft²

520,000

Podium Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

The Hub on Causeway - Podium

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 46,839

48,980

Residential Tower Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Hub50House

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 45,414

47,774

Hotel Tower Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

The Hub on Causeway - Hotel Air Rights

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 12,366

11,505

Office Tower Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 59,716

57,687

1265 Main Office JV LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

1265 Main Street

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 3,465

3,541

BNY Tower Holdings LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Dock 72

Ownership Percentage

^[5]

50.00%

Investments in unconsolidated joint ventures

^[1]

$ (19,921)

28,412

CA-Colorado Center LLC[Member]

Schedule of Equity Method Investments [Line Items]

Properties

Colorado Center

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 233,862

231,479

7750 Wisconsin Avenue LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

7750 Wisconsin Avenue

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 52,152

61,626

BP-M 3HB Venture LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

3 Hudson Boulevard

Ownership Percentage

25.00%

Investments in unconsolidated joint ventures

^[1]

$ 116,397

116,306

SMBP Venture LP [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Santa Monica Business Park

Ownership Percentage

55.00%

Investments in unconsolidated joint ventures

^[1]

$ 164,735

156,639

Platform 16 Holdings LP [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Platform 16

Ownership Percentage

^[6]

55.00%

Investments in unconsolidated joint ventures

^[1]

$ 158,109

109,086

Gateway Portfolio Holdings LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Gateway Commons

Ownership Percentage

^[7]

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 324,038

327,148

Rosecrans-Sepulveda Partners 4, LLC

Schedule of Equity Method Investments [Line Items]

Properties

Beach Cities Media Campus

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 27,000

27,106

Entity Owning Land And Infrastructure Of Project [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

33.33%

Safeco Plaza REIT LLC

Schedule of Equity Method Investments [Line Items]

Properties

Safeco Plaza

Ownership Percentage

^[8]

33.67%

Investments in unconsolidated joint ventures

^[1]

$ 69,785

72,545

Safeco Plaza REIT LLC | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

33.00%

360 PAS Holdco LLC

Schedule of Equity Method Investments [Line Items]

Properties

360 Park Avenue South

Ownership Percentage

^[9]

42.21%

Investments in unconsolidated joint ventures

^[1]

$ 114,992

$ 106,855

360 PAS Holdco LLC | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

35.79%

360 PAS Holdco LLC | Joint Venture Partner [Member] | Scenario, Plan

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

58.00%

Safeco Partner Entity One [Member] | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

1.00%

Safeco Partner Entity Two | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

1.00%

360 PAS Holdco LLC (indirect ownership) | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

5.837%

360 Park Avenue South Partners Entity | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

1.00%

360 Park Avenue South Partners Entity Two | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

1.00%

PR II BXP Reston Gateway LLC

Schedule of Equity Method Investments [Line Items]

Properties

Reston Next Residential

Ownership Percentage

^[10]

20.00%

Investments in unconsolidated joint ventures

^[1]

$ 11,351

PR II BXP Reston Gateway LLC | Joint Venture Partner [Member] | Scenario, Plan

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

80.00%

751 Gateway Holdings LLC

Schedule of Equity Method Investments [Line Items]

Properties

751 Gateway

Ownership Percentage

^[7]

49.00%

Investments in unconsolidated joint ventures

^[1]

$ 80,714

200 Fifth Avenue JV LLC

Schedule of Equity Method Investments [Line Items]

Properties

200 Fifth Avenue

Ownership Percentage

26.69%

Investments in unconsolidated joint ventures

^[1]

$ 120,083

Office Tower Developer LLC

Schedule of Equity Method Investments [Line Items]

Properties

100 Causeway Street

[1]	Investments with deficit balances aggregating approximately $85.4 million and $37.1 million at December 31, 2022 and December 31, 2021, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.
[2]	The Company’s economic ownership has increased based on the achievement of certain return thresholds. At December 31, 2022 and December 31, 2021, the Company’s economic ownership was approximately 50%.
[3]	The Company’s wholly-owned subsidiary that owns Wisconsin Place Office also owns a 33.33% interest in the joint venture entity that owns the land, parking garage and infrastructure of the project.
[4]	Under the joint venture agreement for this land parcel, the partner will be entitled to up to two additional payments from the venture based on increases in total entitled square footage of the project in excess of 520,000 square feet and achieving certain project returns at stabilization.
[5]	This property includes net equity balances from the amenity joint venture.
[6]	This entity is a VIE (See Note 2).
[7]	On June 16, 2022, in accordance with the Gateway Commons joint venture agreement, 751 Gateway was segregated into a new single-purpose joint venture.
[8]	The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture.
[9]	The Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 5.837% indirect ownership in the joint venture, and (3) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture. The Company’s partners will fund required capital until their aggregate investment is approximately 58% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.
[10]	The Company’s partner will fund required capital until its aggregate investment is approximately 80% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.

Debt (Tables)

12 Months Ended

Dec. 31, 2022

Debt Disclosure [Abstract]

Schedule Of Aggregate Principal Payments On Mortgage Notes

Contractual aggregate principal payments of mortgage notes payable at December 31, 2022 are as follows (dollars in thousands):


	Principal Payments
2023	$	—
2024	—
2025	—
2026	—
2027	2,300,000
Thereafter	1,000,000
Total aggregate principal payments	3,300,000
Less:
Deferred financing costs, net	27,632
Total carrying value of mortgage notes payable, net	$	3,272,368

Schedule of Long-term Debt Instruments

The following summarizes the unsecured senior notes outstanding as of December 31, 2022 (dollars in thousands):


	Coupon/Stated Rate		Effective Rate(1)		Principal Amount		Maturity Date(2)
10.5 Year Unsecured Senior Notes	3.125	%	3.279	%	$	500,000	September 1, 2023
10.5 Year Unsecured Senior Notes	3.800	%	3.916	%	700,000		February 1, 2024
7 Year Unsecured Senior Notes	3.200	%	3.350	%	850,000		January 15, 2025
10 Year Unsecured Senior Notes	3.650	%	3.766	%	1,000,000		February 1, 2026
10 Year Unsecured Senior Notes	2.750	%	3.495	%	1,000,000		October 1, 2026
5 Year Unsecured Senior Notes	6.750	%	6.924	%	750,000		December 1, 2027
10 Year Unsecured Senior Notes	4.500	%	4.628	%	1,000,000		December 1, 2028
10 Year Unsecured Senior Notes	3.400	%	3.505	%	850,000		June 21, 2029
10.5 Year Unsecured Senior Notes	2.900	%	2.984	%	700,000		March 15, 2030
10.75 Year Unsecured Senior Notes	3.250	%	3.343	%	1,250,000		January 30, 2031
11 Year Unsecured Senior Notes	2.550	%	2.671	%	850,000		April 1, 2032
12 Year Unsecured Senior Notes	2.450	%	2.524	%	850,000		October 1, 2033
Total principal					10,300,000
Less:
Net unamortized discount					14,094
Deferred financing costs, net					47,938
Total					$	10,237,968

_______________

(1)Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.

(2)No principal amounts are due prior to maturity.

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

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+ Details

Earnings Per Share / Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Basic Earnings:
Net income attributable to the company's common shareholders / unitholders	$ 111,882	$ 184,537	$ 848,947	$ 496,223	$ 862,227
Net income attributable to the company's common shareholders / unitholders (in shares / units)			156,726,000	156,116,000	155,432,000
Net income attributable to the company's common shareholders / unitholders (in dollars per share / unit)			$ 5.42	$ 3.18	$ 5.55
Allocation of undistributed earnings to participating securities			$ (891)	$ 0	$ (748)
Allocation of undistributed earnings to participating securities (in shares / units)			0	0	0
Allocation of undistributed earnings to participating securities (in dollars per share / unit)			$ (0.01)	$ 0	$ (0.01)
Net Income Available To Common Stockholders After Allocation of Undistributed Earnings to Participating Securities Basic			$ 848,056	$ 496,223	$ 861,479
Weighted Average Number Of Shares Outstanding After Allocation of Undistributed Earnings to Participating Securities Basic (in shares)			156,726,000	156,116,000	155,432,000
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)			$ 5.41	$ 3.18	$ 5.54
Effect of Dilutive Securities:
Stock Based Compensation			$ 0	$ 0	$ 0
Stock Based Compensation (in shares / units)			411,000	260,000	85,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)			$ (0.01)	$ (0.01)	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders			$ 848,056	$ 496,223	$ 861,479
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (in shares / units)			157,137,000	156,376,000	155,517,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)			$ 5.40	$ 3.17	$ 5.54
Boston Properties Limited Partnership
Redeemable Common Units			17,634,000	17,034,000	17,211,000
Basic Earnings:
Net income attributable to the company's common shareholders / unitholders			$ 957,265	$ 561,993	$ 979,979
Net income attributable to the company's common shareholders / unitholders (in shares / units)	174,423,000		174,360,000	173,150,000	172,643,000
Net income attributable to the company's common shareholders / unitholders (in dollars per share / unit)			$ 5.49	$ 3.25	$ 5.68
Allocation of undistributed earnings to participating securities			$ (991)	$ 0	$ (830)
Allocation of undistributed earnings to participating securities (in shares / units)			0	0	0
Allocation of undistributed earnings to participating securities (in dollars per share / unit)			$ (0.01)	$ 0	$ (0.01)
Net Income Available To Common Stockholders After Allocation of Undistributed Earnings to Participating Securities Basic			$ 956,274	$ 561,993	$ 979,149
Weighted Average Number Of Shares Outstanding After Allocation of Undistributed Earnings to Participating Securities Basic (in shares)			174,360,000	173,150,000	172,643,000
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)			$ 5.48	$ 3.25	$ 5.67
Effect of Dilutive Securities:
Stock Based Compensation			$ 0	$ 0	$ 0
Stock Based Compensation (in shares / units)			411,000	260,000	85,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)			$ (0.01)	$ (0.01)	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders			$ 956,274	$ 561,993	$ 979,149
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (in shares / units)			174,771,000	173,410,000	172,728,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)			$ 5.47	$ 3.24	$ 5.67

Stock Option and Incentive Plan Stock and Units (Narrative) (Details) $ / shares in Units, $ in Thousands					12 Months Ended
	Feb. 04, 2022 USD ($) shares	Feb. 01, 2022 USD ($)	Feb. 05, 2021 USD ($) shares	Feb. 06, 2020 USD ($) shares	Dec. 31, 2022 USD ($) days $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued \| shares					156,836,767	156,623,749
Vesting Period					4 years
Stock based compensation expense					$ 50,700	$ 49,700	$ 43,000
Common Stock, Value, Issued					$ 1,568	$ 1,565
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued \| shares					41,818	57,383	29,630
LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value Of LTIP Units Issued					$ 28,900	$ 23,800	$ 26,300
Weighted average price (per unit) \| $ / shares					$ 103.06	$ 84.43	$ 127.14
Expected life assumed to calculate per unit fair value per LTIP unit (in years)					5 years 8 months 12 days	5 years 8 months 12 days	5 years 8 months 12 days
Risk-free rate					1.71%	0.65%	1.47%
Expected price volatility					31.00%	30.00%	18.00%
MYLTIP 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Final awards percentage of target	69.00%
Value of MYLTIP Awards	$ 8,600
Forfeitures, in units \| shares	144,043
MYLTIP 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Final awards percentage of target			29.20%
Value of MYLTIP Awards			$ 4,600
Forfeitures, in units \| shares			285,925
MYLTIP 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Final awards percentage of target				83.80%
Value of MYLTIP Awards				$ 17,600
Forfeitures, in units \| shares				270,942
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued \| shares					9,813	9,846	7,195
Weighted Average Price of Shares Purchased \| $ / shares					$ 87.30	$ 89.73	$ 90.53
Number of Business Days, Average Closing Price \| days					10
MYLTIP 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of MYLTIP Awards		$ 17,300
Vesting Period		3 years
Boston Properties Limited Partnership \| LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued \| shares					280,616	281,640	207,181
Boston Properties Limited Partnership \| MYLTIP 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued \| shares					254,061
Boston Properties Limited Partnership \| MYLTIP 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued \| shares						352,021
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee and director payment per share (in dollars per share) \| $ / shares					$ 0.01
Common Stock, Value, Issued					$ 4,700	$ 5,800	$ 4,000
Common Stock Weighted Average Price (in dollars per share) \| $ / shares					$ 111.47	$ 100.60	$ 133.81
LTIP and MYLTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee and director payment per share (in dollars per share) \| $ / shares					$ 0.25
Ltips (including vested MYLTIPS) And Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses					$ 20,600
Unvested MYLTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses					$ 4,900
Weighted-average period (years)					1 year 10 months 24 days

Stock Option and Incentive Plan (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Feb. 01, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	May 20, 2021	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period		4 years
Beginning outstanding, shares		103,641	103,641	351,561		395,353
Weighted Average Exercise Price		$ 97.01	$ 97.01	$ 96.97		$ 96.37
MYLTIP 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	The 2022 MYLTIP awards consist of two, equally weighted (50% each) components that utilize BXP’s TSR over a three-year measurement period as the performance metric. The first component of the 2022 MYLTIP represents one-half (50%) of the target grant-date value of the award. The number of LTIP Units that can be earned under this component ranges from zero to 200% of the target number of LTIP Units, based on BXP’s three-year, annualized relative TSR performance compared to a custom index of peer companies. Under this component, 100% of the target number of LTIP Units will be earned if BXP’s TSR equals the custom index TSR; for relative TSR performance between -1,000 basis points and +1,000 basis points, the number of LTIP Units earned will be determined using linear interpolation.The second component represents the remaining one-half (50%) of the target grant-date value of the 2022 MYLTIP. The number of LTIP Units that can be earned under this component ranges from zero to 200% of the target number of LTIP Units, based on BXP’s non-annualized, cumulative absolute TSR during the three-year performance period. Under this component, 100% of the target number of LTIP Units will be earned if BXP achieves an absolute TSR equal to +1,000 basis points; if BXP’s absolute TSR is greater than -4,000 basis points but less than +6,000 basis points, then the number of LTIP Units earned will be determined using linear interpolation.
Distributions percent before measurement date	10.00%
Vesting Period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights	Earned awards (if any) will vest 100% on January 31, 2025, but may not be converted, redeemed, sold or otherwise transferred for one additional year thereafter. Vesting will be accelerated in the event of a change in control, termination of employment by BXP without cause, or termination of employment by the award recipient for good reason, death, disability or retirement. If there is a change of control prior to January 31, 2025, earned awards will be calculated based on TSR performance up to the date of the change of control.
Value of MYLTIP Awards	$ 17.3
MYLTIP 2022 \| Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued		254,061
MYLTIP 2021 \| Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued			352,021
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance		250,000
Employee discount		85.00%
Number of shares issued		9,813	9,846	7,195
Weighted Average Price of Shares Purchased		$ 87.30	$ 89.73	$ 90.53
stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted		0	0	0
MYLTIP 2020 [Member] \| Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued				203,278
Minimum [Member] \| MYLTIP 2022 \| Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	0
Maximum [Member] \| MYLTIP 2022 \| Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	254,061
Maximum [Member] \| 2021 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance					5,400,000
Target \| MYLTIP 2022 \| Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	127,031

Stockholders' Equity / Partners' Capital (Tables)

12 Months Ended

Dec. 31, 2022

Class of Stock [Line Items]

Dividends Declared [Table Text Block]

The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared during the years ended December 31, 2022, 2021 and 2020:


Record Date	Payment Date	Dividend (Per Share)	Distribution (Per Unit)
December 30, 2022	January 30, 2023	$0.98	$0.98
September 30, 2022	October 31, 2022	$0.98	$0.98
June 30, 2022	July 29, 2022	$0.98	$0.98
March 31, 2022	April 29, 2022	$0.98	$0.98
December 31, 2021	January 28, 2022	$0.98	$0.98
September 30, 2021	October 29, 2021	$0.98	$0.98
June 30, 2021	July 30, 2021	$0.98	$0.98
March 31, 2021	April 30, 2021	$0.98	$0.98
December 31, 2020	January 28, 2021	$0.98	$0.98
September 30, 2020	October 30, 2020	$0.98	$0.98
June 30, 2020	July 31, 2020	$0.98	$0.98
March 31, 2020	April 30, 2020	$0.98	$0.98
December 31, 2019	January 30, 2020	$0.98	$0.98

Series B Preferred Stock [Member]

Class of Stock [Line Items]

Dividends Declared [Table Text Block]

The following table presents BXP’s dividend per share on its Series B Preferred Stock paid during the years ended December 31, 2021 and 2020:

Record Date

Payment Date

Dividend (Per Share)

February 5, 2021

February 16, 2021

$32.8125

November 4, 2020

November 16, 2020

$32.8125

August 3, 2020

August 17, 2020

$32.8125

May 1, 2020

May 15, 2020

$32.8125

February 4, 2020

February 18, 2020

$32.8125

Noncontrolling Interests (Narrative) (Details) - Boston Properties Limited Partnership	Dec. 31, 2022 shares
OP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	16,531,172
LTIP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	1,679,175
2012 OPP and 2013-2019 MYLTIP
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	464,036
MYLTIP 2020 [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	203,278
MYLTIP 2021
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	350,989
MYLTIP 2022
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	253,453

(Common Units) (Narrative) (Details) $ / shares in Units, $ in Thousands						12 Months Ended
	Feb. 04, 2022 USD ($) shares	Feb. 01, 2022 USD ($)	Dec. 14, 2021 USD ($) shares	Feb. 05, 2021 USD ($) shares	Feb. 06, 2020 USD ($) shares	Dec. 31, 2022 USD ($) yr shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($)	Dec. 30, 2022 $ / shares
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Vesting Period						4 years
Issuance of operating partnership units for 360 Park Avenue South \| $						$ 0	$ 99,689	$ 0
360 Park South Avenue
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Issuance of operating partnership units for 360 Park Avenue South \| $			$ 99,700
Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Issuance of operating partnership units for 360 Park Avenue South \| $						0	99,689	$ 0
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount \| $						$ 1,280,886	$ 2,078,603
Boston Properties Limited Partnership \| 360 Park South Avenue
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Shares Issued \| shares			866,503
MYLTIP \| Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Vesting Period						3 years
Unvested MYLTIP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
unvested MYLTIP distributions as compared to total distributions (percentage)						10.00%
MYLTIP 2017 [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Final awards percentage of target					83.80%
Value of MYLTIP Awards \| $					$ 17,600
Forfeitures, in units \| shares					270,942
MYLTIP 2018
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Final awards percentage of target				29.20%
Value of MYLTIP Awards \| $				$ 4,600
Forfeitures, in units \| shares				285,925
MYLTIP 2019 [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Final awards percentage of target	69.00%
Value of MYLTIP Awards \| $	$ 8,600
Forfeitures, in units \| shares	144,043
MYLTIP 2020 [Member] \| Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding \| shares						203,278
MYLTIP 2021 \| Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding \| shares						350,989
MYLTIP 2022
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Vesting Period		3 years
Value of MYLTIP Awards \| $		$ 17,300
MYLTIP 2022 \| Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding \| shares						253,453
OP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
OP Units for redemption (in shares) \| shares						182,929	523,969
Restriction on redemption of OP Unit to Common Stock (in years) \| yr						1
Redemption of OP Unit equivalent to Common Stock (in shares) \| shares						1
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount \| $						$ 1,300,000
Closing price of common stock (in dollars per share) \| $ / shares									$ 67.58
Noncontrolling Interest [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Issuance of operating partnership units for 360 Park Avenue South \| $							$ 99,689
Vested 2012 OPP units and MYLTIPS
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
OP Units for redemption (in shares) \| shares						78,249	148,442

Real Estate (Tables)

12 Months Ended

Dec. 31, 2022

Real Estate Properties [Line Items]

Schedule of Real Estate Properties

BXP

Real estate consisted of the following at December 31, 2022 and December 31, 2021 (in thousands):


	December 31, 2022		December 31, 2021
Land	$	5,189,811	$	5,061,169
Right of use assets - finance leases	237,510		237,507
Right of use assets - operating leases	167,351		169,778
Land held for future development (1)	721,501		560,355
Buildings and improvements	15,820,724		14,291,214
Tenant improvements	3,200,743		2,894,025
Furniture, fixtures and equipment	50,310		51,695
Construction in progress	406,574		894,172
Total	25,794,524		24,159,915
Less: Accumulated depreciation	(6,298,082)		(5,883,961)
	$	19,496,442	$	18,275,954

_______________

(1)Includes pre-development costs.

Madison Centre

Real Estate Properties [Line Items]

Asset Acquisition [Table Text Block]

The following table summarizes the allocation of the purchase price, including transaction costs, of Madison Centre at the date of acquisition (in thousands):


Land	$	104,641
Building and improvements	505,766
Tenant improvements	58,570
In-place lease intangibles	74,598
Above-market lease intangibles	3,794
Below-market lease intangibles	(23,114)
Net assets acquired	$	724,255

125 Broadway

Real Estate Properties [Line Items]

Asset Acquisition [Table Text Block]

The following table summarizes the allocation of the purchase price, including transaction costs, of 125 Broadway at the date of acquisition (in thousands):


Land	$	126,364
Building and improvements	403,588
Tenant improvements	30,074
In-place lease intangibles	49,137
Below-market lease intangibles	(16,725)
Net assets acquired	$	592,438

Madison Centre and 125 Broadway

Real Estate Properties [Line Items]

Schedule of Finite-Lived Intangible Assets Acquired

The following table summarizes the estimated annual amortization of the acquired in-place lease intangibles and the acquired above- and below-market lease intangibles for Madison Centre and 125 Broadway as of their acquisition dates for each of the five succeeding fiscal years (in thousands):


	Acquired In-Place Lease Intangibles	Acquired Above-Market Lease Intangibles	Acquired Below-Market Lease Intangible
2023	20,940	1,098	6,417
2024	19,582	254	6,386
2025	19,510	254	6,373
2026	19,046	254	6,185
2027	17,901	254	5,780

Boston Properties Limited Partnership

Real Estate Properties [Line Items]

Schedule of Real Estate Properties

BPLP

Real estate consisted of the following at December 31, 2022 and December 31, 2021 (in thousands):


	December 31, 2022		December 31, 2021
Land	$	5,095,102	$	4,964,986
Right of use assets - finance leases	237,510		237,507
Right of use assets - operating leases	167,351		169,778
Land held for future development (1)	721,501		560,355
Buildings and improvements	15,547,919		14,014,010
Tenant improvements	3,200,743		2,894,025
Furniture, fixtures and equipment	50,310		51,695
Construction in progress	406,574		894,172
Total	25,427,010		23,786,528
Less: Accumulated depreciation	(6,180,474)		(5,772,018)
	$	19,246,536	$	18,014,510

_______________

(1)Includes pre-development costs.

Segment Information Narrative (Details) $ in Millions	12 Months Ended
Segment Information Narrative (Details) $ in Millions	Dec. 31, 2022 USD ($)
Parking and Other [Member]
Segment Reporting Information [Line Items]
Increase (decrease) in parking and other revenue	$ 25.4

Leases (Details) - USD ($) $ in Thousands	12 Months Ended
Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Fixed contractual payments	$ 2,426,007	$ 2,319,362	$ 2,211,915
Variable lease payments	492,361	433,652	434,346
Lease	$ 2,918,368	$ 2,753,014	$ 2,646,261

Real Estate

12 Months Ended

Dec. 31, 2022

Real Estate [Abstract]

Real Estate

3. Real Estate

BXP

Real estate consisted of the following at December 31, 2022 and December 31, 2021 (in thousands):


	December 31, 2022		December 31, 2021
Land	$	5,189,811	$	5,061,169
Right of use assets - finance leases	237,510		237,507
Right of use assets - operating leases	167,351		169,778
Land held for future development (1)	721,501		560,355
Buildings and improvements	15,820,724		14,291,214
Tenant improvements	3,200,743		2,894,025
Furniture, fixtures and equipment	50,310		51,695
Construction in progress	406,574		894,172
Total	25,794,524		24,159,915
Less: Accumulated depreciation	(6,298,082)		(5,883,961)
	$	19,496,442	$	18,275,954

_______________

(1)Includes pre-development costs.

BPLP

Real estate consisted of the following at December 31, 2022 and December 31, 2021 (in thousands):


	December 31, 2022		December 31, 2021
Land	$	5,095,102	$	4,964,986
Right of use assets - finance leases	237,510		237,507
Right of use assets - operating leases	167,351		169,778
Land held for future development (1)	721,501		560,355
Buildings and improvements	15,547,919		14,014,010
Tenant improvements	3,200,743		2,894,025
Furniture, fixtures and equipment	50,310		51,695
Construction in progress	406,574		894,172
Total	25,427,010		23,786,528
Less: Accumulated depreciation	(6,180,474)		(5,772,018)
	$	19,246,536	$	18,014,510

_______________

(1)Includes pre-development costs.

Acquisitions

On May 17, 2022, the Company completed the acquisition of Madison Centre in Seattle, Washington for a net purchase price, including transaction costs, of approximately $724.3 million. The acquisition was completed using the proceeds from BPLP’s $730.0 million unsecured term loan (See Note 7). Madison Centre is an approximately 755,000 net rentable square foot, 37-story, LEED-Platinum certified, premier workplace. The following table summarizes the allocation of the purchase price, including transaction costs, of Madison Centre at the date of acquisition (in thousands):


Land	$	104,641
Building and improvements	505,766
Tenant improvements	58,570
In-place lease intangibles	74,598
Above-market lease intangibles	3,794
Below-market lease intangibles	(23,114)
Net assets acquired	$	724,255

On September 16, 2022, the Company acquired 125 Broadway in Cambridge, Massachusetts for a net purchase price, including transaction costs, of approximately $592.4 million. The acquisition was completed with available cash and borrowings under BPLP’s unsecured credit facility. 125 Broadway is a 271,000 net rentable square foot, six-story, laboratory/life sciences property. The following table summarizes the allocation of the purchase price, including transaction costs, of 125 Broadway at the date of acquisition (in thousands):


Land	$	126,364
Building and improvements	403,588
Tenant improvements	30,074
In-place lease intangibles	49,137
Below-market lease intangibles	(16,725)
Net assets acquired	$	592,438


	Acquired In-Place Lease Intangibles	Acquired Above-Market Lease Intangibles	Acquired Below-Market Lease Intangible
2023	20,940	1,098	6,417
2024	19,582	254	6,386
2025	19,510	254	6,373
2026	19,046	254	6,185
2027	17,901	254	5,780

125 Broadway contributed approximately $11.4 million of revenue and approximately $3.3 million of net income to the Company for the period from September 16, 2022 through December 31, 2022. Madison Centre contributed approximately $32.0 million of revenue and approximately $2.1 million of net income to the Company for the period from May 17, 2022 through December 31, 2022.

Dispositions

On March 31, 2022, the Company completed the sale of 195 West Street located in Waltham, Massachusetts for a gross sale price of $37.7 million. Net cash proceeds totaled approximately $35.4 million, resulting in a gain on sale of real estate totaling approximately $22.7 million for BXP and approximately $23.4 million for BPLP. 195 West Street is an approximately 63,500 net rentable square foot office property. 195 West Street contributed approximately $0.4 million of net income to the Company from January 1, 2022 through March 30, 2022 and contributed approximately $0.5 million and $(0.8) million of net income (loss) to the Company for the years ended December 31, 2021 and 2020, respectively.

On April 19, 2021, the Company entered into an agreement to acquire 11251 Roger Bacon Drive in Reston, Virginia for an aggregate purchase price of approximately $5.6 million. On April 7, 2022, the Company executed an agreement to assign its right to acquire 11251 Roger Bacon Drive to a third party for an assignment fee of approximately $6.9 million. Net cash proceeds totaled approximately $6.6 million and are reflected as Other income - assignment fee in the Company's Consolidated Statements of Operations. 11251 Roger Bacon Drive is an approximately 65,000 square foot office building situated on approximately 2.6 acres.

On June 15, 2022, the Company completed the sale of its suburban Virginia 95 Office Park properties located in Springfield, Virginia for an aggregate gross sale price of $127.5 million. Net cash proceeds totaled approximately $121.9 million, resulting in a gain on sale of real estate totaling approximately $96.2 million for BXP and approximately $99.5 million for BPLP. Virginia 95 Office Park consists of eleven office/flex properties aggregating approximately 733,000 net rentable square feet. Virginia 95 Office Park contributed approximately $2.3 million of net income to the Company from January 1, 2022 through June 14, 2022 and contributed approximately $7.0 million and $7.8 million of net income to the Company for the years ended December 31, 2021 and 2020, respectively.

On August 30, 2022, the Company completed the sale of 601 Massachusetts Avenue located in Washington, DC for a gross sale price of $531.0 million. Net cash proceeds totaled approximately $512.3 million, resulting in a gain on sale of real estate of approximately $237.4 million for BXP and approximately $237.5 million for BPLP. 601 Massachusetts Avenue is an approximately 479,000 net rentable square foot premier workplace. 601 Massachusetts Avenue contributed approximately $14.9 million of net income to the Company for the period from January 1, 2022 through August 29, 2022, respectively, and contributed approximately $22.4 million and $21.8 million of net income to the Company for the years ended December 31, 2021 and 2020, respectively.

On September 15, 2022, the Company completed the sale of two parcels of land located in Loudoun County, Virginia for an aggregate gross sale price of $27.0 million. Net cash proceeds totaled approximately $25.6 million, resulting in a gain on sale of real estate totaling approximately $24.4 million for BXP and BPLP.

On November 8, 2022, the Company completed the sale of the residential component of The Avant at Reston Town Center, located in Reston, Virginia, for a gross sale price of $141.0 million. Net cash proceeds totaled approximately $139.6 million, resulting in a gain on sale of real estate of approximately $55.6 million for BXP and BPLP. The Avant at Reston Town Center is a 15-story, 359-unit, luxury multifamily building consisting of approximately 329,000 net rentable square feet, excluding retail space. The Company retained ownership of the approximately 26,000 square foot ground-level retail space. The Avant at Reston Town Center contributed approximately $4.1 million of net income to the Company for the period from January 1, 2022 through November 7, 2022, respectively, and contributed approximately $4.0 million and $4.0 million of net income to the Company for the years ended December 31, 2021 and 2020, respectively.

Developments/Redevelopments

On April 27, 2022, the Company entered into a 15-year lease agreement with AstraZeneca for approximately 566,000 net rentable square feet at the Company’s 290 Binney Street future development project. 290 Binney Street is part of the initial phase of a future life sciences development project located in the heart of Kendall Square in Cambridge, Massachusetts. The full project is expected to consist of two buildings aggregating approximately 1.1 million rentable square feet of life sciences space and an approximately 400,000 square foot residential building (See Note 16).

On April 29, 2022, the Company partially placed in-service 2100 Pennsylvania Avenue, a premier workplace project with approximately 480,000 net rentable square feet located in Washington, DC.

On May 13, 2022, the Company commenced the development of Reston Next Office Phase II, a premier workplace project located in Reston, Virginia. When completed, the building will consist of approximately 90,000 net rentable square feet.

On June 29, 2022, the Company completed and fully placed in-service 325 Main Street, a premier workplace project with approximately 414,000 net rentable square feet located in Cambridge, Massachusetts.

On July 1, 2022, the Company commenced the redevelopment of 140 Kendrick Street, a premier workplace that consists of three buildings aggregating approximately 388,000 net rentable square feet located in Needham, Massachusetts. The redevelopment is a repositioning of one building consisting of approximately 90,000 net rentable square feet into a net zero, carbon neutral premier workplace building, as defined by the LEED Zero Carbon Certification. When completed, the building will consist of approximately 104,000 net rentable square feet.

On September 8, 2022, the Company terminated its existing lease agreement with its tenant at 300 Binney Street to facilitate the conversion and expansion of the property. 300 Binney Street is a premier workplace with approximately 195,000 net rentable square feet at Kendall Center in Cambridge, Massachusetts that will be redeveloped into approximately 240,000 net rentable square feet of laboratory/life sciences space (See Note 16).

On September 12, 2022, the Company commenced the redevelopment of 760 Boylston Street, a retail project at the Prudential Center located in Boston, Massachusetts. The redevelopment is a modernization of the space consisting of approximately 118,000 net rentable square feet.

On October 19, 2022, the Company completed and fully placed in-service Reston Next, a premier workplace project consisting of two buildings with an aggregate of approximately 1.1 million net rentable square feet, located in Reston, Virginia.

On November 30, 2022, the Company commenced the redevelopment of 105 Carnegie Center, located in Princeton, New Jersey. The redevelopment is a repositioning of the property. 105 Carnegie Center consisted of approximately 70,000 net rentable square feet of office space. When completed, the building will consist of approximately 73,000 net rentable square feet of laboratory/life sciences space.

On December 1, 2022, the Company removed 2096 Gaither Road from its in-service portfolio following the expiration of the last leases on November 30, 2022. 2096 Gaither Road consisted of approximately 50,000 net rentable square feet of office space in the Company’s Shady Grove Innovation District, located in Rockville, Maryland. The Company anticipates it will redevelop or convert 2096 Gaither Road to support lab or life sciences-related uses.

On December 23, 2022, the Company completed and fully placed in-service 880 Winter Street, an approximately 244,000 net rentable square foot laboratory/life sciences project located in Waltham, Massachusetts.

Consolidated Statements Of Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock [Member]	Preferred Stock [Member]	Additional Paid-In Capital [Member]	Dividends In Excess Of Earnings [Member]	Dividends In Excess Of Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Treasury Stock, at cost [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member] Cumulative Effect, Period of Adoption, Adjustment	Noncontrolling interest - property partnerships [Member]
Equity, shares at Dec. 31, 2019			154,790,000
Equity, value at Dec. 31, 2019	$ 8,014,236	$ (1,679)	$ 1,548	$ 200,000	$ 6,294,719	$ (760,523)	$ (1,505)	$ (2,722)	$ (48,335)	$ 600,860	$ (174)	$ 1,728,689
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List] \| Accounting Standards Update 2018-09
Redemption of operating partnership units to common stock, shares			857,000
Redemption of operating partnership units to common stock, value	$ 0		$ 9		29,689					(29,698)
Allocated net income for the period	1,018,691					872,727				97,704		48,260
Dividends declared	(689,273)					(620,352)				(68,921)
Shares issued pursuant to stock purchase plan, shares			7,000
Shares issued pursuant to stock purchase plan, value	759				759
Net activity from stock option and incentive plan, shares			65,000
Net activity from stock option and incentive plan, value	48,621				9,303					39,318
Issuance of operating partnership units for 360 Park Avenue South	0
Preferred Stock Redemption Charge	0
Contributions from noncontrolling interests in property partnerships	8,219											8,219
Distributions to noncontrolling interests in property partnerships	(58,811)											(58,811)
Effective portion of interest rate contracts	(7,848)								(7,066)	(782)
Amortization of interest rate contracts	6,697								5,511	610		576
Reallocation of noncontrolling interest	0				22,321					(22,321)
Equity, shares at Dec. 31, 2020			155,719,000
Equity, value at Dec. 31, 2020	8,339,612		$ 1,557	200,000	6,356,791	(509,653)		(2,722)	(49,890)	616,596		1,726,933
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of operating partnership units to common stock, shares			524,000
Redemption of operating partnership units to common stock, value	0		$ 5		18,381					(18,386)
Allocated net income for the period	631,932					505,195				55,931		70,806
Dividends declared	(683,843)					(615,021)				(68,822)
Shares issued pursuant to stock purchase plan, shares			9,000
Shares issued pursuant to stock purchase plan, value	1,004				1,004
Net activity from stock option and incentive plan, shares			293,000
Net activity from stock option and incentive plan, value	71,383		$ 3		25,607					45,773
Issuance of operating partnership units for 360 Park Avenue South	99,689									99,689
Preferred Stock, Redeemed	(193,623)			(200,000)	6,377
Preferred Stock Redemption Charge	(6,412)					(6,412)
Contributions from noncontrolling interests in property partnerships	18,002											18,002
Distributions to noncontrolling interests in property partnerships	(259,764)											(259,764)
Effective portion of interest rate contracts	8,544								7,703	841
Amortization of interest rate contracts	6,704								5,525	603		576
Reallocation of noncontrolling interest	$ 0				89,570					(89,570)
Equity, shares at Dec. 31, 2021	156,544,849		156,545,000
Equity, value at Dec. 31, 2021	$ 8,033,228		$ 1,565	0	6,497,730	(625,891)		(2,722)	(36,662)	642,655		1,556,553
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of operating partnership units to common stock, shares			182,000
Redemption of operating partnership units to common stock, value	0		$ 3		6,536					(6,539)
Allocated net income for the period	1,020,584					848,947				96,780		74,857
Dividends declared	(686,126)					(614,412)				(71,714)
Shares issued pursuant to stock purchase plan, shares			10,000
Shares issued pursuant to stock purchase plan, value	1,036				1,036
Net activity from stock option and incentive plan, shares			21,000
Net activity from stock option and incentive plan, value	53,663				7,261					46,402
Issuance of operating partnership units for 360 Park Avenue South	0
Preferred Stock Redemption Charge	0
Contributions from noncontrolling interests in property partnerships	849											849
Distributions to noncontrolling interests in property partnerships	(85,518)											(85,518)
Effective portion of interest rate contracts	19,396								17,435	1,961
Amortization of interest rate contracts	6,707								5,509	622		576
Reallocation of noncontrolling interest	$ 0				26,584					(26,584)
Equity, shares at Dec. 31, 2022	156,757,867		156,758,000
Equity, value at Dec. 31, 2022	$ 8,363,819		$ 1,568	$ 0	$ 6,539,147	$ (391,356)		$ (2,722)	$ (13,718)	$ 683,583		$ 1,547,317

Earnings Per Share / Common Unit (Tables)

12 Months Ended

Dec. 31, 2022

Entity Information [Line Items]

Computation Of Basic And Diluted Earnings Per Share / Unit


	Year ended December 31, 2022
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	848,947	156,726	$	5.42
Allocation of undistributed earnings to participating securities	(891)		—	(0.01)
Net income attributable to Boston Properties, Inc. common shareholders	848,056		156,726	5.41
Effect of Dilutive Securities:
Stock Based Compensation	—		411	(0.01)
Diluted Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	848,056	157,137	$	5.40

	Year ended December 31, 2021
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	496,223	156,116	$	3.18
Allocation of undistributed earnings to participating securities	—		—	—
Net income attributable to Boston Properties, Inc. common shareholders	$	496,223	156,116	$	3.18
Effect of Dilutive Securities:
Stock Based Compensation	—		260	(0.01)
Diluted Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	496,223	156,376	$	3.17

	Year ended December 31, 2020
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	862,227	155,432	$	5.55
Allocation of undistributed earnings to participating securities	(748)		—	(0.01)
Net income attributable to Boston Properties, Inc. common shareholders	$	861,479	155,432	$	5.54
Effect of Dilutive Securities:
Stock Based Compensation	—		85	—
Diluted Earnings:
Net income attributable to Boston Properties, Inc. common shareholders	$	861,479	155,517	$	5.54

Boston Properties Limited Partnership

Entity Information [Line Items]

Computation Of Basic And Diluted Earnings Per Share / Unit


	Year ended December 31, 2022
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	957,265	174,360	$	5.49
Allocation of undistributed earnings to participating securities	(991)		—	(0.01)
Net income attributable to Boston Properties Limited Partnership common unitholders	$	956,274	174,360	$	5.48
Effect of Dilutive Securities:
Stock Based Compensation	—		411	(0.01)
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	956,274	174,771	$	5.47

	Year ended December 31, 2021
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	561,993	173,150	$	3.25
Allocation of undistributed earnings to participating securities	—		—	—
Net income attributable to Boston Properties Limited Partnership common unitholders	$	561,993	173,150	$	3.25
Effect of Dilutive Securities:
Stock Based Compensation	—		260	(0.01)
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	561,993	173,410	$	3.24


	Year ended December 31, 2020
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	979,979	172,643	$	5.68
Allocation of undistributed earnings to participating securities	(830)		—	(0.01)
Net income attributable to Boston Properties Limited Partnership common unitholders	$	979,149	172,643	$	5.67
Effect of Dilutive Securities:
Stock Based Compensation	—		85	—
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	979,149	172,728	$	5.67

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,789,029 and $6,702,830 at December 31, 2022 and December 31, 2021, respectively)	$ 25,389,663	$ 23,752,630
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at December 31, 2022 and December 31, 2021, respectively)	237,510	237,507
Right of use assets - operating leases	167,351	169,778
Less: accumulated depreciation (amounts related to VIEs of $(1,381,401) and $(1,283,060) at December 31, 2022 and December 31, 2021, respectively)	(6,298,082)	(5,883,961)
Total real estate	19,496,442	18,275,954
Cash and cash equivalents (amounts related to VIEs of $259,658 and $300,937 at December 31, 2022 and December 31, 2021, respectively)	690,333	452,692
Cash held in escrows	46,479	48,466
Investments in securities	32,277	43,632
Tenant and other receivables, net (amounts related to VIEs of $16,521 and $6,824 at December 31, 2022 and December 31, 2021, respectively)	81,389	70,186
Related party note receivable, net	78,576	78,336
Notes receivable, net	0	9,641
Sales-type lease receivable, net	12,811	0
Accrued rental income, net (amounts related to VIEs of $367,138 and $357,395 at December 31, 2022 and December 31, 2021, respectively)	1,276,580	1,226,745
Deferred charges, net (amounts related to VIEs of $176,597 and $174,637 at December 31, 2022 and December 31, 2021, respectively)	733,282	618,798
Prepaid expenses and other assets (amounts related to VIEs of $11,647 and $29,668 at December 31, 2022 and December 31, 2021, respectively)	43,589	57,811
Investments in unconsolidated joint ventures	1,715,911	1,482,997
Total assets	24,207,669	22,365,258
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)	3,272,368	3,267,914
Unsecured senior notes, net	10,237,968	9,483,695
Unsecured line of credit	0	145,000
Unsecured term loan	730,000	0
Lease liabilities - finance leases (amounts related to VIEs of $20,604 and $20,458 at December 31, 2022 and December 31, 2021, respectively)	249,335	244,421
Lease liabilities - operating leases	204,686	204,561
Accounts payable and accrued expenses (amounts related to VIEs of $29,466 and $29,464 at December 31, 2022 and December 31, 2021, respectively)	417,545	320,775
Dividends and distributions payable	170,643	169,859
Accrued interest payable	103,774	94,796
Other liabilities (amounts related to VIEs of $114,232 and $150,131 at December 31, 2022 and December 31, 2021, respectively)	450,918	391,441
Total liabilities	15,837,237	14,322,462
Redeemable deferred stock units— 97,853 and 83,073 units outstanding at redemption value at December 31, 2022 and December 31, 2021, respectively	$ 6,613	$ 9,568
Excess stock, shares outstanding	0	0
Excess stock, shares issued	0	0
Preferred stock / units, shares / units issued (in shares / units)	0	0
Preferred stock / units, shares / units outstanding (in shares / units)	0	0
Equity / Capital:
Excess stock, $0.01 par value, 150,000,000 shares authorized, none issued or outstanding	$ 0	$ 0
Preferred stock, $0.01 par value, 50,000,000 shares authorized, none issued or outstanding	0	0
Common stock, $0.01 par value, 250,000,000 shares authorized, 156,836,767 and 156,623,749 issued and 156,757,867 and 156,544,849 outstanding at December 31, 2022 and December 31, 2021, respectively	1,568	1,565
Additional paid-in capital	6,539,147	6,497,730
Dividends in excess of earnings	(391,356)	(625,891)
Treasury common stock at cost, 78,900 shares at December 31, 2022 and December 31, 2021	(2,722)	(2,722)
Accumulated other comprehensive loss	(13,718)	(36,662)
Total stockholders' equity attributable to Boston Properties, Inc.	6,132,919	5,834,020
Noncontrolling interests:
Common units of the Operating Partnership	683,583	642,655
Property partnerships	1,547,317	1,556,553
Total equity / capital	8,363,819	8,033,228
Total liabilities and equity / capital	24,207,669	22,365,258
Boston Properties Limited Partnership
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,789,029 and $6,702,830 at December 31, 2022 and December 31, 2021, respectively)	25,022,149	23,379,243
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at December 31, 2022 and December 31, 2021, respectively)	237,510	237,507
Right of use assets - operating leases	167,351	169,778
Less: accumulated depreciation (amounts related to VIEs of $(1,381,401) and $(1,283,060) at December 31, 2022 and December 31, 2021, respectively)	(6,180,474)	(5,772,018)
Total real estate	19,246,536	18,014,510
Cash and cash equivalents (amounts related to VIEs of $259,658 and $300,937 at December 31, 2022 and December 31, 2021, respectively)	690,333	452,692
Cash held in escrows	46,479	48,466
Investments in securities	32,277	43,632
Tenant and other receivables, net (amounts related to VIEs of $16,521 and $6,824 at December 31, 2022 and December 31, 2021, respectively)	81,389	70,186
Related party note receivable, net	78,576	78,336
Notes receivable, net	0	9,641
Sales-type lease receivable, net	12,811	0
Accrued rental income, net (amounts related to VIEs of $367,138 and $357,395 at December 31, 2022 and December 31, 2021, respectively)	1,276,580	1,226,745
Deferred charges, net (amounts related to VIEs of $176,597 and $174,637 at December 31, 2022 and December 31, 2021, respectively)	733,282	618,798
Prepaid expenses and other assets (amounts related to VIEs of $11,647 and $29,668 at December 31, 2022 and December 31, 2021, respectively)	43,589	57,811
Investments in unconsolidated joint ventures	1,715,911	1,482,997
Total assets	23,957,763	22,103,814
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)	3,272,368	3,267,914
Unsecured senior notes, net	10,237,968	9,483,695
Unsecured line of credit	0	145,000
Unsecured term loan	730,000	0
Lease liabilities - finance leases (amounts related to VIEs of $20,604 and $20,458 at December 31, 2022 and December 31, 2021, respectively)	249,335	244,421
Lease liabilities - operating leases	204,686	204,561
Accounts payable and accrued expenses (amounts related to VIEs of $29,466 and $29,464 at December 31, 2022 and December 31, 2021, respectively)	417,545	320,775
Dividends and distributions payable	170,643	169,859
Accrued interest payable	103,774	94,796
Other liabilities (amounts related to VIEs of $114,232 and $150,131 at December 31, 2022 and December 31, 2021, respectively)	450,918	391,441
Total liabilities	15,837,237	14,322,462
Redeemable deferred stock units— 97,853 and 83,073 units outstanding at redemption value at December 31, 2022 and December 31, 2021, respectively	6,613	9,568
Noncontrolling interest:
Redeemable partnership units— 16,531,172 and 16,561,186 common units and 1,679,175 and 1,485,376 long term incentive units outstanding at redemption value at December 31, 2022 and December 31, 2021, respectively	1,280,886	2,078,603
Equity / Capital:
Boston Properties Limited Partnership partners’ capital— 1,749,682 and 1,745,914 general partner units and 155,008,185 and 154,798,935 limited partner units outstanding at December 31, 2022 and December 31, 2021, respectively	5,299,428	4,173,290
Accumulated other comprehensive loss	(13,718)	(36,662)
Total partners’ capital	5,285,710	4,136,628
Noncontrolling interests in property partnerships	1,547,317	1,556,553
Noncontrolling interests:
Total equity / capital	6,833,027	5,693,181
Total liabilities and equity / capital	$ 23,957,763	$ 22,103,814

Employee Benefits Plan	12 Months Ended
Employee Benefits Plan	Dec. 31, 2022
Disclosure Text Block Supplement [Abstract]
Employee Benefit Plans	13. Employee Benefit Plans Effective January 1, 1985, the predecessor of the Company adopted a 401(k) Savings Plan (the “Plan”) for its employees. Upon formation, the Company adopted the Plan and the terms of the Plan. Under the Plan, as amended, the Company’s matching contribution equals 200% of the first 3% of participant’s eligible earnings contributed (utilizing earnings that are not in excess of an amount established by the IRS ($305,000, $290,000 and $285,000 in 2022, 2021 and 2020, respectively), indexed for inflation) with no vesting requirement. The Company’s aggregate matching contribution for the years ended December 31, 2022, 2021 and 2020 was approximately $4.8 million, $4.7 million and $4.0 million, respectively. The Company also maintains a deferred compensation plan that is designed to allow officers of BXP to defer a portion of the officer’s current income on a pre-tax basis and receive a tax-deferred return on these deferrals based on the performance of specific investments selected by the officer. The Company’s obligation under the plan is that of an unsecured promise to pay the deferred compensation to the plan participants in the future. At December 31, 2022 and 2021, the Company had maintained approximately $31.7 million and $42.7 million, respectively, in a separate account, which is not restricted as to its use. The Company’s liability under the plan is equal to the total amount of compensation deferred by the plan participants and earnings on the deferred compensation pursuant to investments elected by the plan participants. The Company’s liability as of December 31, 2022 and 2021 was approximately $31.7 million and $42.7 million, respectively, which are included in the accompanying Consolidated Balance Sheets.

Summary Of Significant Accounting Policies Schedule of Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2022
Tenant improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	Shorter of useful life or terms of related lease
Minimum [Member] \| Land Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
Minimum [Member] \| Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Minimum [Member] \| Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member] \| Land Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Maximum [Member] \| Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Maximum [Member] \| Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years

Consolidated Statements Of Cash Flows $ in Thousands	12 Months Ended
Consolidated Statements Of Cash Flows $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Net income	$ 1,020,584	$ 631,932	$ 1,018,691
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	749,775	717,336	683,751
Amortization of right of use assets - operating leases	2,427	3,516	2,234
Non-cash compensation expense	52,026	50,860	44,142
Loss from unconsolidated joint ventures	59,840	2,570	85,110
Distributions of net cash flow from operations of unconsolidated joint ventures	26,827	21,542	31,892
Losses (gains) from investments in securities	6,453	(5,626)	(5,261)
Allowance for current expected credit losses	(224)	(1,207)	1,849
Non-cash portion of interest expense	25,831	23,368	23,384
Settlement of accreted debt discount on redemption of unsecured senior notes	0	(8,500)	0
Losses from early extinguishment of debt	0	45,182	0
Other Income - assignment fee	6,624	0	0
Gains on sales of real estate	(437,019)	(123,660)	(618,982)
Gain on sales-type lease	(10,058)	0	0
Unrealized loss on non-real estate investment	150	0	0
Change in assets and liabilities:
Tenant and other receivables, net	(7,621)	4,820	22,550
Notes receivable, net	(152)	(545)	(19)
Accrued rental income, net	(98,075)	(101,548)	(97,099)
Prepaid expenses and other assets	20,099	(20,811)	12,488
Lease liabilities - finance leases	0	0	568
Lease liabilities - operating leases	125	(23,599)	1,533
Accounts payable and accrued expenses	(22,777)	20,025	(4,059)
Accrued interest payable	8,989	(10,839)	16,211
Other liabilities	(24,120)	(28,739)	17,629
Tenant leasing costs	(84,057)	(62,850)	(79,772)
Total adjustments	261,815	501,295	138,149
Net cash provided by operating activities	1,282,399	1,133,227	1,156,840
Cash flows from investing activities:
Acquisitions of real estate	(1,320,273)	(222,260)	(137,976)
Construction in progress	(500,273)	(513,878)	(482,507)
Building and other capital improvements	(177,004)	(150,998)	(160,126)
Tenant improvements	(218,685)	(263,952)	(234,423)
Proceeds from sales of real estate	834,770	179,887	519,303
Proceeds from assignment fee	6,624	0	0
Capital contributions to unconsolidated joint ventures	(277,581)	(98,152)	(172,436)
Capital distributions from unconsolidated joint ventures	37,122	122	55,298
Proceeds from sale of investment in unconsolidated joint venture	0	17,789	0
Investments in non-real estate investments	(2,404)	0	0
Issuance of notes receivable, net	0	0	(9,800)
Proceeds from note receivable	10,000	10,035	6,397
Investments in securities, net	4,902	1,451	2,551
Net cash used in investing activities	(1,602,802)	(1,039,956)	(613,719)
Cash flows from financing activities:
Proceeds from Secured Notes Payable	0	1,201,388	0
Repayments of mortgage notes payable	0	(832,296)	(17,168)
Proceeds from unsecured senior notes	749,557	1,695,996	1,248,125
Redemption of unsecured senior notes	0	(1,841,500)	0
Borrowings on unsecured line of credit	985,000	770,000	265,000
Repayments of unsecured line of credit	(1,130,000)	(625,000)	(265,000)
Borrowings on unsecured term loan	730,000	0	0
Redemption of preferred stock	0	(200,000)	0
Payments on finance lease obligations	0	1,250	0
Repayment of unsecured term loan	0	(500,000)	0
Deferred financing costs	(8,460)	(20,757)	(10,416)
Debt Issuance Costs	0	(16,186)	0
Debt prepayment and extinguishment costs	0	(43,036)	0
Net activity from equity transactions	(352)	24,214	3,277
Dividends and distributions	(685,019)	(683,753)	(688,904)
Contributions from noncontrolling interests in property partnerships	849	18,002	8,219
Distributions to noncontrolling interests in property partnerships	(85,518)	(259,764)	(58,811)
Net cash provided by (used in) financing activities	556,057	(1,311,442)	484,322
Net increase (decrease) in cash and cash equivalents and cash held in escrows	235,654	(1,218,171)	1,027,443
Cash and cash equivalents and cash held in escrows, beginning of period	501,158	1,719,329	691,886
Cash and cash equivalents and cash held in escrows, end of period	736,812	501,158	1,719,329
Reconciliation of cash and cash equivalents and cash held in escrow
Cash and cash equivalents, beginning of period	452,692	1,668,742	644,950
Cash held in escrows, beginning of period	48,466	50,587	46,936
Cash and cash equivalents, end of period	690,333	452,692	1,668,742
Cash held in escrows,end of period	46,479	48,466	50,587
Supplemental disclosures:
Cash paid for interest	449,903	465,442	433,492
Interest capitalized	52,130	53,097	53,881
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(119,534)	(239,317)	(99,494)
Change in real estate included in accounts payable and accrued expenses	97,586	(25,183)	(19,848)
Construction in progress, net deconsolidated	(11,316)	(299,947)	0
Investment in unconsolidated joint ventures recorded upon deconsolidation	11,316	107,132	347,898
Sales-type lease origination	13,045	0	0
Derecognition of assets in exchange for sales-type lease obligation	(2,987)	0	0
Accrued rental income, net deconsolidated	0	0	(4,558)
Tenant leasing costs, net deconsolidated	0	0	(3,462)
Building and other capital improvements, net deconsolidated	0	0	(111,889)
Tenant improvements, net deconsolidated	0	0	(12,331)
Prepaid expenses and other assets, net deconsolidated	0	(5,011)	0
Assumption of mortgage notes payable	0	200,311	0
Mortgage notes payable, net deconsolidation	0	(198,381)	0
Issuance of operating partnership units	0	99,689	0
Right-of-use assets obtained in exchange for lease liabilities	0	26,887	0
Dividends and distributions declared but not paid	170,643	169,859	171,082
Conversions of noncontrolling interests to stockholders’ equity	6,539	18,386	29,698
Issuance of restricted securities to employees and non-employee directors	48,417	44,405	42,607
Boston Properties Limited Partnership
Net income	1,032,122	641,771	1,038,739
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	742,293	709,035	676,666
Amortization of right of use assets - operating leases	2,427	3,516	2,234
Non-cash compensation expense	52,026	50,860	44,142
Loss from unconsolidated joint ventures	59,840	2,570	85,110
Distributions of net cash flow from operations of unconsolidated joint ventures	26,827	21,542	31,892
Losses (gains) from investments in securities	6,453	(5,626)	(5,261)
Allowance for current expected credit losses	(224)	(1,207)	1,849
Non-cash portion of interest expense	25,831	23,368	23,384
Settlement of accreted debt discount on redemption of unsecured senior notes	0	(8,500)	0
Losses from early extinguishment of debt	0	45,182	0
Other Income - assignment fee	6,624	0	0
Gains on sales of real estate	(441,075)	(125,198)	(631,945)
Gain on sales-type lease	(10,058)	0	0
Unrealized loss on non-real estate investment	150	0	0
Change in assets and liabilities:
Tenant and other receivables, net	(7,621)	4,820	22,550
Notes receivable, net	(152)	(545)	(19)
Accrued rental income, net	(98,075)	(101,548)	(97,099)
Prepaid expenses and other assets	20,099	(20,811)	12,488
Lease liabilities - finance leases	0	0	568
Lease liabilities - operating leases	125	(23,599)	1,533
Accounts payable and accrued expenses	(22,777)	20,025	(4,059)
Accrued interest payable	8,989	(10,839)	16,211
Other liabilities	(24,120)	(28,739)	17,629
Tenant leasing costs	(84,057)	(62,850)	(79,772)
Total adjustments	250,277	491,456	118,101
Net cash provided by operating activities	1,282,399	1,133,227	1,156,840
Cash flows from investing activities:
Acquisitions of real estate	(1,320,273)	(222,260)	(137,976)
Construction in progress	(500,273)	(513,878)	(482,507)
Building and other capital improvements	(177,004)	(150,998)	(160,126)
Tenant improvements	(218,685)	(263,952)	(234,423)
Proceeds from sales of real estate	834,770	179,887	519,303
Proceeds from assignment fee	6,624	0	0
Capital contributions to unconsolidated joint ventures	(277,581)	(98,152)	(172,436)
Capital distributions from unconsolidated joint ventures	37,122	122	55,298
Proceeds from sale of investment in unconsolidated joint venture	0	17,789	0
Investments in non-real estate investments	(2,404)	0	0
Issuance of notes receivable, net	0	0	(9,800)
Proceeds from note receivable	10,000	10,035	6,397
Investments in securities, net	4,902	1,451	2,551
Net cash used in investing activities	(1,602,802)	(1,039,956)	(613,719)
Cash flows from financing activities:
Proceeds from Secured Notes Payable	0	1,201,388	0
Repayments of mortgage notes payable	0	(832,296)	(17,168)
Proceeds from unsecured senior notes	749,557	1,695,996	1,248,125
Redemption of unsecured senior notes	0	(1,841,500)	0
Borrowings on unsecured line of credit	985,000	770,000	265,000
Repayments of unsecured line of credit	(1,130,000)	(625,000)	(265,000)
Borrowings on unsecured term loan	730,000	0	0
Redemption of preferred stock	0	(200,000)	0
Payments on finance lease obligations	0	1,250	0
Repayment of unsecured term loan	0	(500,000)	0
Deferred financing costs	(8,460)	(20,757)	(10,416)
Debt Issuance Costs	0	(16,186)	0
Debt prepayment and extinguishment costs	0	(43,036)	0
Net activity from equity transactions	(352)	24,214	3,277
Dividends and distributions	(685,019)	(683,753)	(688,904)
Contributions from noncontrolling interests in property partnerships	849	18,002	8,219
Distributions to noncontrolling interests in property partnerships	(85,518)	(259,764)	(58,811)
Net cash provided by (used in) financing activities	556,057	(1,311,442)	484,322
Net increase (decrease) in cash and cash equivalents and cash held in escrows	235,654	(1,218,171)	1,027,443
Cash and cash equivalents and cash held in escrows, beginning of period	501,158	1,719,329	691,886
Cash and cash equivalents and cash held in escrows, end of period	736,812	501,158	1,719,329
Reconciliation of cash and cash equivalents and cash held in escrow
Cash and cash equivalents, beginning of period	452,692	1,668,742	644,950
Cash held in escrows, beginning of period	48,466	50,587	46,936
Cash and cash equivalents, end of period	690,333	452,692	1,668,742
Cash held in escrows,end of period	46,479	48,466	50,587
Supplemental disclosures:
Cash paid for interest	449,903	465,442	433,492
Interest capitalized	52,130	53,097	53,881
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(119,534)	(238,003)	(99,494)
Change in real estate included in accounts payable and accrued expenses	97,586	(25,183)	(19,848)
Construction in progress, net deconsolidated	(11,316)	(299,947)	0
Investment in unconsolidated joint ventures recorded upon deconsolidation	11,316	107,132	347,898
Sales-type lease origination	13,045	0	0
Derecognition of assets in exchange for sales-type lease obligation	(2,987)	0	0
Accrued rental income, net deconsolidated	0	0	(4,558)
Tenant leasing costs, net deconsolidated	0	0	(3,462)
Building and other capital improvements, net deconsolidated	0	0	(111,889)
Tenant improvements, net deconsolidated	0	0	(12,331)
Prepaid expenses and other assets, net deconsolidated	0	(5,011)	0
Assumption of mortgage notes payable	0	200,311	0
Mortgage notes payable, net deconsolidation	0	(198,381)	0
Issuance of operating partnership units	0	99,689	0
Right-of-use assets obtained in exchange for operating lease liabilities	0	26,887	0
Dividends and distributions declared but not paid	170,643	169,859	171,082
Conversions of noncontrolling interests to stockholders’ equity	6,539	18,386	29,698
Issuance of restricted securities to employees and non-employee directors	$ 48,417	$ 44,405	$ 42,607

Lessee, Lease Cost and Other Information (Details)
$ in Thousands

12 Months Ended

Dec. 31, 2022

USD ($)

Dec. 31, 2021

USD ($)

Dec. 31, 2020

USD ($)

Lessee, Lease, Description [Line Items]

Operating lease costs

$ 12,700

$ 13,151

$ 13,948

Amortization of right-of-use asset

^[1]

697

547

Interest on lease liabilities

^[2]

$ 3,236

$ 2,471

$ 583

Operating leases, Weighted-average remaining lease term

49 years

50 years

Finance leases, Weighted-average remaining lease term

68 years

69 years

Operating leases, Weighted-average discount rate

5.70%

Finance leases, Weighted-average discount rate

6.20%

Finance leases under development

[1]

The finance leases relate to either land, buildings or assets that remain in development. For land leases classified as finance leases because of a purchase option that the Company views as an economic incentive, the Company follows its existing policy and does not depreciate land because it is assumed to have an indefinite life. For all other finance leases, the Company would amortize the right of use asset over the shorter of the useful life of the asset or the lease term. If the finance lease relates to a property under development, the amortization of the right of use asset may be eligible for capitalization. For assets under development, depreciation may commence once the asset is placed in-service and depreciation would be recognized in accordance with the Company’s policy.

[2]

One, two and three of the finance leases relate to assets under development for all or a portion of the years ended December 31, 2022, December 31, 2021 and December 31, 2020, respectively, and as such, a portion of the interest amount was capitalized.

Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2022	Feb. 21, 2023	Jun. 30, 2022
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Document Transition Report	false
Entity File Number	1-13087
Entity Registrant Name	BOSTON PROPERTIES, INC.
Entity Central Index Key	0001037540
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-2473675
Entity Address, Address Line One	Prudential Center, 800 Boylston Street, Suite 1900
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02199-8103
City Area Code	617
Local Phone Number	236-3300
Title of 12(b) Security	Common Stock, par value $.01 per share
Entity Listing, Par Value Per Share	$ 0.01
Trading Symbol	BXP
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 13,917,004,905
Documents Incorporated by Reference	Certain information contained in Boston Properties Inc.’s Proxy Statement relating to its Annual Meeting of Stockholders to be held May 23, 2023 is incorporated by reference in Items 10, 11, 12, 13 and 14 of Part III. Boston Properties, Inc. intends to file such Proxy Statement with the Securities and Exchange Commission not later than 120 days after the end of its fiscal year ended December 31, 2022.
Entity Common Stock, Shares Outstanding		156,822,702
Boston Properties Limited Partnership
Entity Information [Line Items]
Document Type	10-K
Document Period End Date	Dec. 31, 2022
Entity File Number	0-50209
Entity Registrant Name	BOSTON PROPERTIES LIMITED PARTNERSHIP
Entity Central Index Key	0001043121
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3372948
Title of 12(g) Security	Units of Limited Partnership
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false

Lessor Leases Narrative (Details)		12 Months Ended
Lessor Leases Narrative (Details)	Dec. 19, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jul. 29, 2020 ft² room
Lessor, Lease, Description [Line Items]
Sales-type lease receivable, net	$ 13,000,000	$ 13,028,000
Sales-type Lease, Unguaranteed Residual Asset	17,000	17,000
Gain on sales-type lease	$ 10,100,000	$ 10,058,000	$ 0	$ 0
Third-party hotel developer
Lessor, Lease, Description [Line Items]
Number of Units in Real Estate Property \| room					267
Net Rentable Area (in sf) \| ft²					241,000
Land
Lessor, Lease, Description [Line Items]
Lessor, Sales-type Lease, Term of Contract					99 years

Consolidated Statements Of Operations - USD ($)
shares in Thousands

12 Months Ended

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Revenue

Lease

$ 2,918,368,000

$ 2,753,014,000

$ 2,646,261,000

Total revenue

3,108,581,000

2,888,621,000

2,765,686,000

Expenses

Rental

1,108,070,000

1,021,151,000

1,017,208,000

General and administrative

146,378,000

151,573,000

133,112,000

Transaction costs

2,905,000

5,036,000

1,531,000

Depreciation and amortization

749,775,000

717,336,000

683,751,000

Total expenses

2,050,056,000

1,920,581,000

1,860,364,000

Other income (expense)

Loss from Unconsolidated Joint Ventures

(59,840,000)

(2,570,000)

(85,110,000)

Gains on sales of real estate

437,019,000

123,660,000

618,982,000

Gain on sales-type lease

10,058,000

Interest and other income (loss)

11,940,000

5,704,000

5,953,000

Other Income - assignment fee

6,624,000

Gains (losses) from investments in securities

(6,453,000)

5,626,000

5,261,000

Unrealized loss on non-real estate investment

(150,000)

Losses from early extinguishment of debt

(45,182,000)

Interest expense

(437,139,000)

(423,346,000)

(431,717,000)

Net income

1,020,584,000

631,932,000

1,018,691,000

Net income attributable to noncontrolling interests

Noncontrolling interests in property partnerships

(74,857,000)

(70,806,000)

(48,260,000)

Noncontrolling interest - common units of the Operating Partnership

(96,780,000)

(55,931,000)

(97,704,000)

Net income attributable to the Company

848,947,000

505,195,000

872,727,000

Preferred dividends / distributions

(2,560,000)

(10,500,000)

Preferred Stock Redemption Charge

(6,412,000)

Net income attributable to the Company's common shareholders / unitholders

$ 848,947,000

$ 496,223,000

$ 862,227,000

Basic earnings per common share / unit attributable to the Company

Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)

$ 5.41

$ 3.18

$ 5.54

Weighted average number of common shares / units outstanding (in shares / units)

156,726

156,116

155,432

Diluted earnings per common share / unit attributable to the Company

Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)

$ 5.40

$ 3.17

$ 5.54

Weighted average number of common and common equivalent shares / units outstanding (in shares / units)

157,137

156,376

155,517

Boston Properties Limited Partnership

Revenue

Lease

$ 2,918,368,000

$ 2,753,014,000

$ 2,646,261,000

Total revenue

3,108,581,000

2,888,621,000

2,765,686,000

Expenses

Rental

1,108,070,000

1,021,151,000

1,017,208,000

General and administrative

146,378,000

151,573,000

133,112,000

Transaction costs

2,905,000

5,036,000

1,531,000

Depreciation and amortization

742,293,000

709,035,000

Total expenses

2,042,574,000

1,912,280,000

1,853,279,000

Other income (expense)

Loss from Unconsolidated Joint Ventures

(59,840,000)

(2,570,000)

(85,110,000)

Gains on sales of real estate

441,075,000

125,198,000

631,945,000

Gain on sales-type lease

10,058,000

Interest and other income (loss)

11,940,000

5,704,000

5,953,000

Other Income - assignment fee

6,624,000

Gains (losses) from investments in securities

(6,453,000)

5,626,000

5,261,000

Unrealized loss on non-real estate investment

(150,000)

Losses from early extinguishment of debt

(45,182,000)

Interest expense

(437,139,000)

(423,346,000)

(431,717,000)

Net income

1,032,122,000

641,771,000

1,038,739,000

Net income attributable to noncontrolling interests

Noncontrolling interests in property partnerships

(74,857,000)

(70,806,000)

(48,260,000)

Net income attributable to the Company

957,265,000

570,965,000

990,479,000

Preferred dividends / distributions

(2,560,000)

(10,500,000)

Preferred Stock Redemption Charge

(6,412,000)

Net income attributable to the Company's common shareholders / unitholders

$ 957,265,000

$ 561,993,000

$ 979,979,000

Basic earnings per common share / unit attributable to the Company

Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)

$ 5.48

$ 3.25

$ 5.67

Weighted average number of common shares / units outstanding (in shares / units)

174,360

173,150

172,643

Diluted earnings per common share / unit attributable to the Company

Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)

$ 5.47

$ 3.24

$ 5.67

Weighted average number of common and common equivalent shares / units outstanding (in shares / units)

174,771

173,410

172,728

Parking and Other [Member]

Revenue

Other revenue

$ 107,225,000

$ 81,814,000

$ 70,680,000

Parking and Other [Member] | Boston Properties Limited Partnership

Revenue

Other revenue

107,225,000

81,814,000

70,680,000

Hotel [Member]

Revenue

Other revenue

^[1]

39,482,000

13,609,000

7,478,000

Expenses

Operating expense

27,478,000

12,998,000

13,136,000

Hotel [Member] | Boston Properties Limited Partnership

Revenue

Other revenue

39,482,000

13,609,000

7,478,000

Expenses

Operating expense

27,478,000

12,998,000

13,136,000

Real Estate, Other [Member]

Revenue

Other revenue

15,450,000

12,487,000

11,626,000

Expenses

Operating expense

15,450,000

12,487,000

11,626,000

Real Estate, Other [Member] | Boston Properties Limited Partnership

Revenue

Other revenue

15,450,000

12,487,000

11,626,000

Expenses

Operating expense

15,450,000

12,487,000

11,626,000

Management Service [Member]

Revenue

Other revenue

28,056,000

27,697,000

29,641,000

Management Service [Member] | Boston Properties Limited Partnership

Revenue

Other revenue

$ 28,056,000

$ 27,697,000

$ 29,641,000

[1]	Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

Summary Of Significant Accounting Policies of Tax Treatment of Common Dividends Per Share for Federal Tax Purposes (Details) - $ / shares

12 Months Ended

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Dec. 19, 2022

Summary Of Significant Accounting Policies [Line Items]

Dividends treatment for federal tax purposes.

$ 3.95

^[1]

$ 3.92

^[2]

$ 3.88

^[3]

Dividends Treatment For Federal Tax Purposes, Percentage

100.00%

Distributions Payable, Amount Per Unit

$ 0.98

Ordinary income

Summary Of Significant Accounting Policies [Line Items]

Dividends treatment for federal tax purposes.

$ 3.42

$ 2.90

$ 2.52

Dividends Treatment For Federal Tax Purposes, Percentage

86.60%

73.86%

64.91%

Capital Gain Income

Summary Of Significant Accounting Policies [Line Items]

Dividends treatment for federal tax purposes.

$ 0.53

$ 0.57

$ 0.99

Dividends Treatment For Federal Tax Purposes, Percentage

13.40%

14.57%

25.49%

Return of Capital

Summary Of Significant Accounting Policies [Line Items]

Dividends treatment for federal tax purposes.

$ 0

$ 0.45

$ 0.37

Dividends Treatment For Federal Tax Purposes, Percentage

0.00%

11.57%

9.60%

Dividend Declared

Summary Of Significant Accounting Policies [Line Items]

Distributions Payable, Amount Per Unit

$ 0.98

Allocated to 2022

Summary Of Significant Accounting Policies [Line Items]

Distributions Payable, Amount Per Unit

0.03

Allocated to 2023

Summary Of Significant Accounting Policies [Line Items]

Distributions Payable, Amount Per Unit

$ 0.95

[1]	The fourth quarter 2022 regular quarterly dividend was $0.98 per common share, of which approximately $0.03 per common share was allocable to 2022 and approximately $0.95 per common share was allocable to 2023.
[2]	The fourth quarter 2021 regular quarterly dividend was $0.98 per common share, all of which was allocable to 2022.
[3]	The fourth quarter 2020 regular quarterly dividend was $0.98 per common share, all of which was allocable to 2021.

Related Party Disclosures	12 Months Ended
Related Party Disclosures	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions Disclosure	15. Related Party Transactions A firm controlled by Mr. Raymond A. Ritchey’s brother was paid aggregate leasing commissions of approximately $914,000 during the year ended December 31, 2020 related to certain exclusive leasing arrangements for certain Northern Virginia properties. There were no payments made for the years ended December 31, 2022 and 2021. In addition, Mr. Ritchey’s brother is employed by a real estate brokerage firm and participated in brokerage activities for which the Company paid the firm approximately $1.6 million, $1.9 million and $3.4 million for the years ended December 31, 2022, 2021 and 2020, respectively. Mr. Ritchey is a Senior Executive Vice President of BXP. On July 13, 2018, the Company entered into a joint venture with a third party to acquire a development site at 3 Hudson Boulevard that, upon the future acquisition of additional available development rights, can accommodate an office tower with up to 2.0 million net rentable square feet located on the entire square block between 11th Avenue and Hudson Boulevard Park from West 34th Street to West 35th Street in New York City. The Company owns a 25% interest in, and is the managing member of, the joint venture. The Company provided $80.0 million of mortgage financing to the joint venture that bears interest at a variable rate equal to LIBOR plus 3.50% per annum and matures on July 13, 2023, with extension options, subject to certain conditions. The loan has been reflected as a Related Party Note Receivable, Net on the Company’s Consolidated Balance Sheets. The Company has recognized interest income of approximately $5.6 million, $3.6 million and $2.7 million for the years ended December 31, 2022, 2021 and 2020, respectively. The Company's policy is to record notes receivable at their unamortized cost, net of any unamortized deferred fees or costs, premiums or discounts and an allowance for loan losses. Loan fees and direct costs associated with loans originated by the Company are deferred and amortized over the term of the note as interest income. In accordance with the 2021 Plan, and as approved by its Board of Directors, seven non-employee directors made elections to receive deferred stock units in lieu of cash fees for 2022. As a result of these elections, the aggregate cash fees otherwise payable to a non-employee director during a fiscal quarter are converted into a number of deferred stock units equal to the aggregate cash fees divided by the last reported sales price of a share of BXP’s Common Stock on the last trading of the applicable fiscal quarter. The deferred stock units are also credited with dividend equivalents as dividends are paid by BXP. The deferred stock units may be settled in shares of Common Stock upon the cessation of such director’s service on the Board of Directors of BXP. The non-employee director compensation program provides, subject to certain conditions, the non-employee directors holding deferred stock units with the ability to elect, following cessation of their service on BXP’s Board of Directors, to diversify their investment elections into non-employer securities on a pre-tax basis and receive tax-deferred returns on such deferrals, which will ultimately be settled in cash. The Company’s obligation under the plan is that of an unsecured promise to pay the deferred compensation to the non-employee director in the future. At December 31, 2022 and 2021, the Company had maintained approximately $0.6 million and $0.9 million, respectively, in a separate account, which is not restricted as to its use. The Company’s liability under the plan is equal to the total amount of compensation deferred by the non-employee director and earnings on the deferred compensation pursuant to investments elected by the non-employee director. The Company’s liability as of December 31, 2022 and 2021 was approximately $0.6 million and $0.9 million, respectively, which is included in the accompanying Consolidated Balance Sheets. The terms of the non-employee director compensation program require the classification of these deferred stock units as temporary equity on the Consolidated Balance Sheets of Boston Properties, Inc. and Boston Properties Limited Partnership within Redeemable Deferred Stock Units. On December 16, 2021, in connection with the resignation of a director’s service on the Board of Directors of BXP, BXP issued 498 shares of Common Stock in settlement of the director’s outstanding deferred stock units. At December 31, 2022 and 2021, BXP had outstanding 97,853 and 83,073 deferred stock units, respectively.

Future Minimum Rent (Details) $ in Thousands	12 Months Ended
Future Minimum Rent (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2023	$ 2,338,610
2024	2,321,135
2025	2,279,700
2026	2,212,455
2027	2,094,014
Thereafter	$ 13,020,102
Schedule of Future Minimum Lease Payments
Number Of Tenants Above Concentration Amount.	0	0	0
Revenue Benchmark [Member] \| Customer Concentration Risk
Concentration Risk [Line Items]
Concentration Risk, Percentage	10.00%	10.00%	10.00%

Unsecured Term Loan (Details) - USD ($) $ in Thousands	Dec. 31, 2022	May 17, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Unsecured term loan	$ 730,000	$ 730,000	$ 0
Debt Instrument, Basis Spread on Variable Rate	0.775%
2022 Unsecured Term Loan
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 730,000
Debt Instrument, Maturity Date		May 16, 2023
Debt Instrument, Interest Rate Terms		At BPLP’s option, the 2022 Unsecured Term Loan bore interest at a rate per annum equal to (A) (1) a base rate per annum equal to the greater of (a) the federal funds rate plus 0.5%, (b) the administrative agent’s prime rate, (c) term SOFR plus 1.00% and (d) 1.00%, or (2) a term SOFR rate per annum equal to the forward-looking SOFR term rate administered by CME Group Benchmark Administration (“CME”) two business days prior to the commencement of such interest period; or if the rate was unavailable, then the forward-looking SOFR term rate administered by CME on the first business day immediately prior thereto, in each case, plus 0.10%, and (B) a margin ranging from zero to 160 basis points based on BPLP’s credit rating.
Unsecured term loan	$ 730,000	$ 730,000
2022 Unsecured Term Loan \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.95%

Deferred Charges Schedule of Acquired In-Place Lease Intangibles (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2023	$ 27,659
2024	21,595
2025	21,419
2026	20,571
2027	$ 18,214

SEC Schedule, Article 12-28, Real Estate and Accumulated Depreciation Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward]
Balance at the beginning of the year	$ 24,108,220	$ 23,303,303	$ 22,844,697
Additions to / improvements of real estate	2,228,000	1,145,084	996,989
Assets sold/written-off	(592,006)	(340,167)	(538,383)
Balance at the end of the year	25,744,214	24,108,220	23,303,303
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward]
Balance at the beginning of the year	5,848,183	5,501,637	5,239,179
Depreciation expense	646,020	623,854	573,898
Assets sold/written-off	(233,211)	(277,308)	(311,440)
Balance at the end of the year	6,260,992	5,848,183	5,501,637
Boston Properties Limited Partnership
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward]
Balance at the beginning of the year	23,734,833	22,926,494	22,449,476
Additions to / improvements of real estate	2,228,000	1,145,084	996,989
Assets sold/written-off	(586,133)	(336,745)	(519,971)
Balance at the end of the year	25,376,700	23,734,833	22,926,494
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward]
Balance at the beginning of the year	5,736,240	5,396,111	5,135,289
Depreciation expense	638,538	615,553	566,813
Assets sold/written-off	(231,394)	(275,424)	(305,991)
Balance at the end of the year	$ 6,143,384	$ 5,736,240	$ 5,396,111

Segment Information (Schedule Of Segment Reporting By Geographic Area And Property Type) (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Segment Reporting Information [Line Items]

Rental Revenue: Class A Office

^[1]

$ 2,968,412

$ 2,792,160

$ 2,678,795

Rental Revenue: Residential

^[1]

57,181

42,668

38,146

Rental Revenue Total

^[1]

$ 3,065,075

$ 2,848,437

$ 2,724,419

Rental Revenue: % of Grand Totals

100.00%

Rental Expenses: Class A Office

$ 1,078,487

$ 996,707

$ 998,469

Rental Expenses: Residential

29,583

24,444

18,739

Rental Expenses: Total

$ 1,135,548

$ 1,034,149

$ 1,030,344

Rental Expenses: % Of Grand Totals

100.00%

Net Operating Income

$ 1,929,527

$ 1,814,288

$ 1,694,075

Net Operating Income: % of Grand Totals

100.00%

Company's Share of Net Operating Income: % of Grand Totals

100.00%

Boston [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Class A Office

^[1]

$ 1,005,156

$ 930,560

$ 897,915

Rental Revenue: Residential

^[1]

15,086

13,397

13,616

Rental Revenue Total

^[1]

$ 1,059,724

$ 957,566

$ 919,009

Rental Revenue: % of Grand Totals

34.58%

33.62%

33.73%

Rental Expenses: Class A Office

$ 360,218

$ 322,298

$ 318,509

Rental Expenses: Residential

5,961

5,811

5,378

Rental Expenses: Total

$ 393,657

$ 341,107

$ 337,023

Rental Expenses: % Of Grand Totals

34.66%

32.98%

32.71%

Net Operating Income

$ 666,067

$ 616,459

$ 581,986

Net Operating Income: % of Grand Totals

34.52%

33.98%

34.35%

Company's Share of Net Operating Income: % of Grand Totals

34.75%

33.98%

33.88%

Los Angeles [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Class A Office

^[1]

$ 0

Rental Revenue: Residential

^[1]

Rental Revenue Total

^[1]

$ 0

Rental Revenue: % of Grand Totals

0.00%

Rental Expenses: Class A Office

$ 0

Rental Expenses: Residential

Rental Expenses: Total

$ 0

Rental Expenses: % Of Grand Totals

0.00%

Net Operating Income

$ 0

Net Operating Income: % of Grand Totals

0.00%

Company's Share of Net Operating Income: % of Grand Totals

2.81%

2.98%

3.56%

New York [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Class A Office

^[1]

$ 1,031,479

$ 1,012,172

$ 935,966

Rental Revenue: Residential

^[1]

Rental Revenue Total

^[1]

$ 1,031,479

$ 1,012,172

$ 935,966

Rental Revenue: % of Grand Totals

33.65%

35.53%

34.36%

Rental Expenses: Class A Office

$ 391,293

$ 379,267

$ 384,753

Rental Expenses: Residential

Rental Expenses: Total

$ 391,293

$ 379,267

$ 384,753

Rental Expenses: % Of Grand Totals

34.46%

36.67%

37.35%

Net Operating Income

$ 640,186

$ 632,905

$ 551,213

Net Operating Income: % of Grand Totals

33.18%

34.88%

32.54%

Company's Share of Net Operating Income: % of Grand Totals

26.32%

28.18%

26.12%

San Francisco [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Class A Office

^[1]

$ 534,397

$ 508,620

$ 508,327

Rental Revenue: Residential

^[1]

14,769

3,892

155

Rental Revenue Total

^[1]

$ 549,166

$ 512,512

$ 508,482

Rental Revenue: % of Grand Totals

17.92%

17.99%

18.66%

Rental Expenses: Class A Office

$ 183,353

$ 168,040

$ 163,156

Rental Expenses: Residential

11,371

6,717

2,261

Rental Expenses: Total

$ 194,724

$ 174,757

$ 165,417

Rental Expenses: % Of Grand Totals

17.15%

16.90%

16.05%

Net Operating Income

$ 354,442

$ 337,755

$ 343,065

Net Operating Income: % of Grand Totals

18.37%

18.62%

20.25%

Company's Share of Net Operating Income: % of Grand Totals

19.49%

20.27%

22.02%

Seattle

Segment Reporting Information [Line Items]

Rental Revenue: Class A Office

^[1]

$ 31,978

$ 0

Rental Revenue: Residential

^[1]

Rental Revenue Total

^[1]

$ 31,978

$ 0

Rental Revenue: % of Grand Totals

1.04%

0.00%

Rental Expenses: Class A Office

$ 8,386

$ 0

Rental Expenses: Residential

Rental Expenses: Total

$ 8,386

$ 0

Rental Expenses: % Of Grand Totals

0.74%

0.00%

Net Operating Income

$ 23,592

$ 0

Net Operating Income: % of Grand Totals

1.22%

0.00%

Company's Share of Net Operating Income: % of Grand Totals

1.66%

0.14%

Washington, DC [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Class A Office

^[1]

$ 365,402

$ 340,808

$ 336,587

Rental Revenue: Residential

^[1]

27,326

25,379

24,375

Rental Revenue Total

^[1]

$ 392,728

$ 366,187

$ 360,962

Rental Revenue: % of Grand Totals

12.81%

12.86%

13.25%

Rental Expenses: Class A Office

$ 135,237

$ 127,102

$ 132,051

Rental Expenses: Residential

12,251

11,916

11,100

Rental Expenses: Total

$ 147,488

$ 139,018

$ 143,151

Rental Expenses: % Of Grand Totals

12.99%

13.45%

13.89%

Net Operating Income

$ 245,240

$ 227,169

$ 217,811

Net Operating Income: % of Grand Totals

12.71%

12.52%

12.86%

Company's Share of Net Operating Income: % of Grand Totals

14.97%

14.45%

14.42%

Hotel [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

$ 39,482

$ 13,609

$ 7,478

Operating expense

27,478

12,998

13,136

Hotel [Member] | Boston [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

39,482

13,609

7,478

Operating expense

27,478

12,998

13,136

Hotel [Member] | Los Angeles [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

Operating expense

Hotel [Member] | New York [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

Operating expense

Hotel [Member] | San Francisco [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

Operating expense

Hotel [Member] | Seattle

Segment Reporting Information [Line Items]

Other revenue

^[1]

Operating expense

Hotel [Member] | Washington, DC [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

Operating expense

Noncontrolling interest - property partnerships [Member]

Segment Reporting Information [Line Items]

Net Operating Income

(191,812)

(186,304)

(162,887)

Noncontrolling interest - property partnerships [Member] | Boston [Member]

Segment Reporting Information [Line Items]

Net Operating Income

(45,822)

(43,232)

(41,849)

Noncontrolling interest - property partnerships [Member] | Los Angeles [Member]

Segment Reporting Information [Line Items]

Net Operating Income

Noncontrolling interest - property partnerships [Member] | New York [Member]

Segment Reporting Information [Line Items]

Net Operating Income

(145,990)

(143,072)

(121,038)

Noncontrolling interest - property partnerships [Member] | San Francisco [Member]

Segment Reporting Information [Line Items]

Net Operating Income

Noncontrolling interest - property partnerships [Member] | Seattle

Segment Reporting Information [Line Items]

Net Operating Income

Noncontrolling interest - property partnerships [Member] | Washington, DC [Member]

Segment Reporting Information [Line Items]

Net Operating Income

Unconsolidated Joint Ventures [Member]

Segment Reporting Information [Line Items]

Net Operating Income

146,081

107,756

94,943

Unconsolidated Joint Ventures [Member] | Boston [Member]

Segment Reporting Information [Line Items]

Net Operating Income

34,233

16,551

10,765

Unconsolidated Joint Ventures [Member] | Los Angeles [Member]

Segment Reporting Information [Line Items]

Net Operating Income

53,023

51,641

57,907

Unconsolidated Joint Ventures [Member] | New York [Member]

Segment Reporting Information [Line Items]

Net Operating Income

1,594

(664)

(5,326)

Unconsolidated Joint Ventures [Member] | San Francisco [Member]

Segment Reporting Information [Line Items]

Net Operating Income

12,785

14,152

14,928

Unconsolidated Joint Ventures [Member] | Seattle

Segment Reporting Information [Line Items]

Net Operating Income

7,690

2,498

Unconsolidated Joint Ventures [Member] | Washington, DC [Member]

Segment Reporting Information [Line Items]

Net Operating Income

36,756

23,578

16,669

Company's Share [Member]

Segment Reporting Information [Line Items]

Net Operating Income

1,883,796

1,735,740

1,626,131

Company's Share [Member] | Boston [Member]

Segment Reporting Information [Line Items]

Net Operating Income

654,478

589,778

550,902

Company's Share [Member] | Los Angeles [Member]

Segment Reporting Information [Line Items]

Net Operating Income

53,023

51,641

57,907

Company's Share [Member] | New York [Member]

Segment Reporting Information [Line Items]

Net Operating Income

495,790

489,169

424,849

Company's Share [Member] | San Francisco [Member]

Segment Reporting Information [Line Items]

Net Operating Income

367,227

351,907

357,993

Company's Share [Member] | Seattle

Segment Reporting Information [Line Items]

Net Operating Income

31,282

2,498

Company's Share [Member] | Washington, DC [Member]

Segment Reporting Information [Line Items]

Net Operating Income

$ 281,996

$ 250,747

$ 234,480

[1]	Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

Investments in Unconsolidated Joint Ventures (Statements of Operations of the Joint Ventures) (Details)
$ in Thousands

12 Months Ended

Dec. 31, 2022

USD ($)

Dec. 31, 2021

USD ($)

Dec. 31, 2020

USD ($)

Mar. 30, 2021

Schedule of Equity Method Investments [Line Items]

Total revenue

$ 3,108,581

$ 2,888,621

$ 2,765,686

Expenses

Transaction costs

2,905

5,036

1,531

Depreciation and amortization

749,775

717,336

683,751

Total expenses

2,050,056

1,920,581

1,860,364

Other income (expense)

Losses from early extinguishment of debt

(45,182)

Interest expense

(437,139)

(423,346)

(431,717)

Gains on sales of real estate

437,019

123,660

618,982

Net income

1,020,584

631,932

1,018,691

Income (Loss) from Equity Method Investments

(59,840)

(2,570)

(85,110)

Straight Line Rent Adjustments

108,000

104,300

104,900

Write-off (reinstatement) for accrued rent and accounts receivables

(1,500)

1,300

90,300

Above and below market rent adjustments, net

9,100

4,200

6,500

Unconsolidated Joint Ventures [Member]

Schedule of Equity Method Investments [Line Items]

Total revenue

^[1]

512,078

383,649

319,560

Expenses

Operating

198,632

158,498

144,347

Transaction costs

837

470

1,027

Depreciation and amortization

181,041

147,121

141,853

Total expenses

380,510

306,089

287,227

Other income (expense)

Losses from early extinguishment of debt

(1,327)

Interest expense

(154,065)

(108,884)

(98,051)

Unrealized gain on derivative instruments

1,681

Gains on sales of real estate

11,737

^[2]

Net income

(22,143)

(31,324)

(53,981)

Company's share of net income

(2,551)

(10,254)

(16,256)

Gain on Sale of Investments

10,257

^[3]

Impairment loss on investment

(50,705)

^[4]

(60,524)

^[4]

Basis differential

^[5]

(6,584)

(2,573)

(8,330)

Income (Loss) from Equity Method Investments

(59,840)

(2,570)

(85,110)

Straight Line Rent Adjustments

(62,900)

(17,200)

(10,100)

Above and below market rent adjustments, net

400

$ 900

Parcels of undeveloped land

Annapolis Junction NFM, LLC [Member]

Other income (expense)

Gain on Sale of Investments

10,300

Ownership Percentage

50.00%

Colorado Center [Member] | Unconsolidated Joint Ventures [Member]

Other income (expense)

Straight Line Rent Adjustments

500

$ 800

$ 1,800

Dock 72 [Member] | Unconsolidated Joint Ventures [Member]

Other income (expense)

Impairment loss on investment

$ 50,700

$ 60,500

[1]	Includes straight-line rent adjustments of approximately $62.9 million, $17.2 million and $(10.1) million for the years ended December 31, 2022, 2021 and 2020, respectively.
[2]	For the year ended December 31, 2020, represents the gain on sale of Annapolis Junction Building Eight and two land parcels. The gain on sale of real estate is included in Loss from Unconsolidated Joint Ventures in the Company’s Consolidated Statements of Operations.
[3]	During the year ended December 31, 2021, the Company completed the sale of its 50% ownership interest in Annapolis Junction NFM LLC. The Company recognized a gain on sale of investment of approximately $10.3 million.
[4]	During the years ended December 31, 2022 and December 31, 2020, the Company recognized an other-than-temporary impairment loss on its investment in the unconsolidated joint venture that owns Dock 72 in Brooklyn, New York totaling approximately $50.7 million and $60.5 million, respectively.
[5]	Includes straight-line rent adjustments of approximately $0.5 million, $0.8 million and $1.8 million for the years ended December 31, 2022, 2021 and 2020, respectively. Also includes net above-/below-market rent adjustments of approximately $0.4 million, $0.4 million and $0.9 million for the years ended December 31, 2022, 2021 and 2020, respectively.

Deferred Charges (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Leasing costs, including lease related intangibles	$ 1,095,231	$ 1,011,229
Financing costs	19,311	19,231
Deferred Costs Gross	1,114,542	1,030,460
Less: Accumulated amortization	(381,260)	(411,662)
Deferred Costs, total	$ 733,282	$ 618,798

Summary Of Significant Accounting Policies (Carrying Value Of Indebtedness And Corresponding Estimate Of Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	May 17, 2022	Dec. 31, 2021
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable, net	$ 78,576		$ 78,336
Notes receivable, net	0		9,641
Sales-type lease receivable, net	12,811		0
Mortgage notes payable, net	3,272,368		3,267,914
Unsecured senior notes, net	10,237,968		9,483,695
Unsecured line of credit	0		145,000
Unsecured term loan, net	730,000	$ 730,000	0
Carrying Amount [Member]
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable, net	78,576		78,336
Notes receivable, net	0		9,641
Sales-type lease receivable, net	12,811		0
Total	91,387		87,977
Mortgage notes payable, net	3,272,368		3,267,914
Unsecured senior notes, net	10,237,968		9,483,695
Unsecured line of credit	0		145,000
Unsecured term loan, net	730,000		0
Total	14,240,336		12,896,609
Estimated Fair Value [Member]
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable, net	79,220		82,867
Notes receivable, net	0		10,000
Sales-type lease receivable, net	13,045		0
Total	92,265		92,867
Mortgage notes payable, net	2,744,479		3,395,569
Unsecured senior notes, net	9,135,512		9,966,591
Unsecured line of credit	0		145,317
Unsecured term loan, net	730,000		0
Total	$ 12,609,991		$ 13,507,477

Noncontrolling Interests (Tables)

12 Months Ended

Dec. 31, 2022

Noncontrolling Interest [Line Items]

Distribution Declared to OP, LTIP, OPP and MYLTIP Units [Table Text Block]

The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared during the years ended December 31, 2022, 2021 and 2020:


Record Date	Payment Date	Dividend (Per Share)	Distribution (Per Unit)
December 30, 2022	January 30, 2023	$0.98	$0.98
September 30, 2022	October 31, 2022	$0.98	$0.98
June 30, 2022	July 29, 2022	$0.98	$0.98
March 31, 2022	April 29, 2022	$0.98	$0.98
December 31, 2021	January 28, 2022	$0.98	$0.98
September 30, 2021	October 29, 2021	$0.98	$0.98
June 30, 2021	July 30, 2021	$0.98	$0.98
March 31, 2021	April 30, 2021	$0.98	$0.98
December 31, 2020	January 28, 2021	$0.98	$0.98
September 30, 2020	October 30, 2020	$0.98	$0.98
June 30, 2020	July 31, 2020	$0.98	$0.98
March 31, 2020	April 30, 2020	$0.98	$0.98
December 31, 2019	January 30, 2020	$0.98	$0.98

Noncontrolling Interests [Member]

Noncontrolling Interest [Line Items]

Distribution Declared to OP, LTIP, OPP and MYLTIP Units [Table Text Block]


Record Date	Payment Date	Distributions per OP Unit and LTIP Unit	Distributions per MYLTIP Unit
December 30, 2022	January 30, 2023	$0.98	$0.098
September 30, 2022	October 31, 2022	$0.98	$0.098
June 30, 2022	July 29, 2022	$0.98	$0.098
March 31, 2022	April 29, 2022	$0.98	$0.098
December 31, 2021	January 28, 2022	$0.98	$0.098


Record Date	Payment Date	Distributions per OP Unit and LTIP Unit	Distributions per MYLTIP Unit
December 31, 2021	January 28, 2022	$0.98	$0.098
September 30, 2021	October 29, 2021	$0.98	$0.098
June 30, 2021	July 30, 2021	$0.98	$0.098
March 31, 2021	April 30, 2021	$0.98	$0.098
December 31, 2020	January 28, 2021	$0.98	$0.098


Record Date	Payment Date	Distributions per OP Unit and LTIP Unit	Distributions per MYLTIP Unit
December 31, 2020	January 28, 2021	$0.98	$0.098
September 30, 2020	October 30, 2020	$0.98	$0.098
June 30, 2020	July 31, 2020	$0.98	$0.098
March 31, 2020	April 30, 2020	$0.98	$0.098
December 31, 2019	January 30, 2020	$0.98	$0.098

Deferred Charges

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Deferred Charges

5. Deferred Charges

Deferred charges consisted of the following at December 31, 2022 and 2021 (in thousands):


	December 31, 2022		December 31, 2021
Leasing costs, including lease related intangibles	$	1,095,231	$	1,011,229
Financing costs	19,311		19,231
	1,114,542		1,030,460
Less: Accumulated amortization	(381,260)		(411,662)
	$	733,282	$	618,798

The following table summarizes the scheduled amortization of the Company’s acquired in-place lease intangibles for each of the five succeeding years (in thousands).


	Acquired In-Place Lease Intangibles
2023	$	27,659
2024	21,595
2025	21,419
2026	20,571
2027	18,214

Investments in Unconsolidated Joint Ventures (Balance Sheets of the Unconsolidated Joint Ventures) (Details) - USD ($)
$ in Thousands

Dec. 31, 2022

Dec. 31, 2021

ASSETS

Total real estate

$ 19,496,442

$ 18,275,954

Total assets

24,207,669

22,365,258

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Mortgage and notes payable, net

3,272,368

3,267,914

Other Liabilities

450,918

391,441

Members’/Partners’ equity

6,132,919

5,834,020

Total liabilities and equity / capital

24,207,669

22,365,258

Carying value of the Company's investment in unconsolidated joint ventures

1,715,911

1,482,997

Right-of-use assets - finance leases

237,510

237,507

Right of use assets - operating leases

167,351

169,778

Lease liabilities - finance leases

249,335

244,421

Lease liabilities - operating leases

204,686

204,561

Unconsolidated Joint Ventures [Member]

ASSETS

Total real estate

^[1]

6,537,554

5,579,218

Other assets

756,786

586,470

Total assets

7,294,340

6,165,688

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Mortgage and notes payable, net

4,022,746

3,214,961

Other Liabilities

^[2]

716,271

652,135

Members’/Partners’ equity

2,555,323

2,298,592

Total liabilities and equity / capital

7,294,340

6,165,688

Company's share of equity

1,238,929

1,104,175

Basis differentials

^[3]

391,556

341,751

Carying value of the Company's investment in unconsolidated joint ventures

^[4]

1,630,485

1,445,926

Right-of-use assets - finance leases

248,900

Right of use assets - operating leases

21,200

22,300

Lease liabilities - finance leases

382,200

385,500

Lease liabilities - operating leases

30,500

30,400

Unconsolidated Joint Ventures [Member]

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Other Liabilities

85,400

37,100

Colorado Center

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

301,820

304,776

Carying value of the Company's investment in unconsolidated joint ventures

^[5]

233,862

231,479

Gateway Commons Complex [Member]

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

47,808

51,009

Carying value of the Company's investment in unconsolidated joint ventures

^[5]

324,038

327,148

Dock 72

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

(98,980)

(50,051)

Carying value of the Company's investment in unconsolidated joint ventures

^[5]

(19,921)

$ 28,412

200 Fifth Avenue JV LLC

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

94,497

Carying value of the Company's investment in unconsolidated joint ventures

^[5]

$ 120,083

[1]

At December 31, 2022 and December 31, 2021, this amount included right of use assets - finance leases totaling approximately $248.9 million. At December 31, 2022 and December 31, 2021, this amount included right of use assets - operating leases totaling approximately $21.2 million and $22.3 million, respectively.

[2]

At December 31, 2022 and December 31, 2021, this amount included lease liabilities - finance leases totaling approximately $382.2 million and $385.5 million, respectively. At December 31, 2022 and December 31, 2021, this amount included lease liabilities - operating leases totaling approximately $30.5 million and $30.4 million, respectively.

[3]

This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The majority of the Company’s basis differences are as follows:


	December 31, 2022		December 31, 2021
Property	(in thousands)
Colorado Center	$	301,820	$	304,776
200 Fifth Avenue	94,497		N/A
Gateway Commons	47,808		51,009
Dock 72	(98,980)		(50,051)

These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

[4]

Investments with deficit balances aggregating approximately $85.4 million and $37.1 million at December 31, 2022 and December 31, 2021, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets.

[5]

Investments with deficit balances aggregating approximately $85.4 million and $37.1 million at December 31, 2022 and December 31, 2021, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.

Employee Benefits Plan (Details) - USD ($) $ in Thousands	12 Months Ended
Employee Benefits Plan (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	200.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.00%
Defined Contribution Plan, Employer Matching Contribution, Eligible Earnings Limit by IRS Amount	$ 305	$ 290	$ 285
Defined Contribution Plan, Employer Discretionary Contribution Amount	4,800	4,700	$ 4,000
Separate Unrestricted Cash For Deferred Compensation Plan.	32,300	43,600
Deferred Compensation Liability, Current and Noncurrent	31,700	42,700
Officer [Member]
Defined Contribution Plan Disclosure [Line Items]
Separate Unrestricted Cash For Deferred Compensation Plan.	$ 31,700	$ 42,700

Commitments And Contingencies (Details) $ in Thousands		12 Months Ended
Commitments And Contingencies (Details) $ in Thousands	Jun. 27, 2022 USD ($)	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 29, 2022 ft²	Jun. 26, 2022 USD ($)	May 09, 2019 ft²
Commitments And Contingencies [Line Items]
Letter of credit and performance obligations		$ 26,500
Notes receivable, net		0	$ 9,641
Proceeds from note receivable		10,000	10,035	$ 6,397
Property insurance program per occurrence limits		1,000,000
Per occurrence limit for NBCR Coverage		1,000,000
Value of program trigger		$ 200,000
Coinsurance of program trigger		20.00%
Program trigger deductible		20.00%
Per occurrence limit of the earthquake insurance which covers San Francisco and Los Angeles regions		$ 330,000
Annual aggregate limit of the earthquake insurance which covers San Francisco and Los Angeles regions		330,000
Amount of earthquake insurance provided by IXP, LLC as direct insurer San Francisco and Los Angeles		$ 30,000
Deductible in insurance as a percentage of the value of the affected property, San Francisco and Los Angeles		3.00%
Per Occurrence Limit of Earthquake Insurance Seattle		$ 110,000
Annual Aggregate Limit of Earthquake Insurance Seattle		$ 110,000
Earthquake Deductible Insurance Percentage of Value of the Affected Property Seattle		2.00%
Affiliate of Bernstein Companies [Member]
Commitments And Contingencies [Line Items]
Notes receivable, net						$ 10,000
Proceeds from note receivable	$ 10,000
Note receivable fixed interest rate						8.00%
Proceeds from Interest Received	$ 1,600
Boston Properties Limited Partnership
Commitments And Contingencies [Line Items]
Notes receivable, net		$ 0	9,641
Proceeds from note receivable		10,000	$ 10,035	$ 6,397
Operating partnership guarantee to cover liabilities of IXP		20,000
767 Venture, LLC [Member]
Commitments And Contingencies [Line Items]
Maximum funding obligation		13,700
Property insurance program per occurrence limits		1,625,000
325 Main Street
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) \| ft²					414,000		115,000
601 Lexington Avenue
Commitments And Contingencies [Line Items]
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP		1,350,000
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Property and Terrorism		750,000
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Terrorism		600,000
Sum of Coverage Covered by IXP and Excess Coverage for Property and Terrorism		$ 1,750,000
Future Residential Building [Member] \| 325 Main Street
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) \| ft²		200,000
Affordable Housing requirement		25.00%
Home Ownership Units [Member] \| Future Residential Building [Member] \| 325 Main Street
Commitments And Contingencies [Line Items]
Affordable Housing requirement		20.00%

Stock Options Outstanding Table (Details) - $ / shares	12 Months Ended
Stock Options Outstanding Table (Details) - $ / shares	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning outstanding, shares	103,641	103,641	351,561	395,353
Weighted Average Exercise Price	$ 97.01	$ 97.01	$ 96.97	$ 96.37
Exercise price $95.69
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning outstanding, shares	54,282
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	3 months 18 days
Weighted Average Exercise Price	$ 95.69
Number Exercisable	54,282
Exercisable, Weighted Average Exercise Price	$ 95.69
Exercise Price $98.46
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning outstanding, shares	49,359
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	1 month 6 days
Weighted Average Exercise Price	$ 98.46
Number Exercisable	49,359
Exercisable, Weighted Average Exercise Price	$ 98.46

Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Summary Of Significant Accounting Policies [Line Items]

Property, Plant and Equipment

Depreciation is computed on a straight-line basis over the estimated useful lives of the assets as follows:


Land improvements						25 to 40 years
Buildings and improvements						10 to 40 years
Tenant improvements						Shorter of useful life or terms of related lease
Furniture, fixtures, and equipment						3 to 7 years

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The following table summarizes the scheduled amortization of the Company’s acquired “above-” and “below-market” lease intangibles for each of the five succeeding years (in thousands).


	Acquired Above-Market Lease Intangibles		Acquired Below-Market Lease Intangibles
2023	$	1,306	$	13,439
2024	401		9,811
2025	389		9,768
2026	389		8,647
2027	389		5,477

Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]

Recurring Fair Value of Financial Instruments


Financial Instrument			Level
Unsecured senior notes (1)			Level 1
Related party note receivable			Level 3
Notes receivable			Level 3
Sales-type lease receivable			Level 3
Mortgage notes payable			Level 3
Unsecured line of credit			Level 3
Unsecured term loan			Level 3

_______________

(1)If trading volume for the period is low, the valuation could be categorized as Level 2.

Fair Value, by Balance Sheet Grouping [Table Text Block]


	December 31, 2022				December 31, 2021
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Related party note receivable, net	$	78,576	$	79,220	$	78,336	$	82,867
Note receivable, net	—		—		9,641		10,000
Sales-type lease receivable, net	12,811		13,045		—		—
Total	$	91,387	$	92,265	$	87,977	$	92,867

Mortgage notes payable, net	$	3,272,368	$	2,744,479	$	3,267,914	$	3,395,569
Unsecured senior notes, net	10,237,968		9,135,512		9,483,695		9,966,591
Unsecured line of credit	—		—		145,000		145,317
Unsecured term loan, net	730,000		730,000		—		—
Total	$	14,240,336	$	12,609,991	$	12,896,609	$	13,507,477

Dividends Declared

The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared during the years ended December 31, 2022, 2021 and 2020:


Record Date	Payment Date	Dividend (Per Share)	Distribution (Per Unit)
December 30, 2022	January 30, 2023	$0.98	$0.98
September 30, 2022	October 31, 2022	$0.98	$0.98
June 30, 2022	July 29, 2022	$0.98	$0.98
March 31, 2022	April 29, 2022	$0.98	$0.98
December 31, 2021	January 28, 2022	$0.98	$0.98
September 30, 2021	October 29, 2021	$0.98	$0.98
June 30, 2021	July 30, 2021	$0.98	$0.98
March 31, 2021	April 30, 2021	$0.98	$0.98
December 31, 2020	January 28, 2021	$0.98	$0.98
September 30, 2020	October 30, 2020	$0.98	$0.98
June 30, 2020	July 31, 2020	$0.98	$0.98
March 31, 2020	April 30, 2020	$0.98	$0.98
December 31, 2019	January 30, 2020	$0.98	$0.98

Dividend Paid [Member]

Summary Of Significant Accounting Policies [Line Items]

Dividends Declared

The tax treatment of common dividends per share for federal income tax purposes is as follows:


	For the year ended December 31,
	2022					2021					2020
	Per Share			%		Per Share			%		Per Share			%
Ordinary income	$	3.42		86.60	%	$	2.90		73.86	%	$	2.52		64.91	%
Capital gain income	0.53			13.40	%	0.57			14.57	%	0.99			25.49	%
Return of capital	—			—	%	0.45			11.57	%	0.37			9.60	%
Total	$	3.95	(1)	100.00	%	$	3.92	(2)	100.00	%	$	3.88	(3)	100.00	%

_____________

(2)The fourth quarter 2021 regular quarterly dividend was $0.98 per common share, all of which was allocable to 2022.

(3)The fourth quarter 2020 regular quarterly dividend was $0.98 per common share, all of which was allocable to 2021.

Organization (Details) ft² in Millions		12 Months Ended
Organization (Details) ft² in Millions	Dec. 31, 2021	Dec. 31, 2022 ft² Real_Estate_Properties yr shares
Real Estate Properties [Line Items]
Restriction on redemption of OP units from date of issuance (years) \| yr		1
One OP unit is equivalent to one share of Common Stock (in shares) \| shares		1
OP unit conversion rate (in shares) \| shares		1
Number of VIEs		7
Variable Interest Entity, Primary Beneficiary [Member]
Real Estate Properties [Line Items]
Number of VIEs		6
Variable Interest Entity, Primary Beneficiary [Member] \| Commercial Real Estate Properties [Member]
Real Estate Properties [Line Items]
Number of VIEs		5
Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties		13
Net Rentable Area (in sf) \| ft²		3.2
Commercial Real Estate Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties		194
Net Rentable Area (in sf) \| ft²		54.1
Office Building [Member]
Real Estate Properties [Line Items]
Number of real estate properties		173
Office Building [Member] \| Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties		10
Retail Site [Member]
Real Estate Properties [Line Items]
Number of real estate properties		14
Retail Site [Member] \| Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties		2
Residential Building
Real Estate Properties [Line Items]
Number of real estate properties		6
Residential Building \| Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties		1
Hotel [Member]
Real Estate Properties [Line Items]
Number of real estate properties		1
Boston Properties Limited Partnership
Real Estate Properties [Line Items]
General and limited partnership interest in the operating partnership (percent)	89.70%	89.60%

Lease Liability Maturity Detail Prior Year (Details) - USD ($)
$ in Thousands

Dec. 31, 2022

Dec. 31, 2021

Lessee, Operating Lease, Liability, Payment, Due [Abstract]

2022

$ 22,415

$ 19,623

2023

22,274

25,333

2024

10,308

10,085

2025

10,100

10,307

2026

9,885

10,100

Thereafter

528,915

538,801

Total lease payments

603,897

614,249

Less: Interest Portion

399,211

409,688

Present value of lease payments

204,686

204,561

Finance Lease, Liability, Payment, Due [Abstract]

2022

9,306

8,762

2023

49,343

^[1]

10,826

2024

9,971

48,605

^[1]

2025

10,166

9,971

2026

10,364

10,166

Thereafter

1,352,647

1,363,011

Total lease payments

1,441,797

1,451,341

Less: Interest Portion

1,192,462

1,206,920

Present value of lease payments

$ 249,335

$ 244,421

[1]	Finance lease payments in 2024 include approximately $38.7 million related to a purchase option that the Company is reasonably certain it will exercise.

Consolidated Statement of Capital and Noncontrolling Interests - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Common Stock, Shares, Outstanding	156,757,867	156,544,849
Net activity from stock option and incentive plan, value	$ 53,663	$ 71,383	$ 48,621
Issuance of operating partnership units for 360 Park Avenue South	0	99,689	0
Preferred Stock Redemption Charge	0	(6,412)	0
Effective portion of interest rate contracts	19,396	8,544	(7,848)
Amortization of interest rate contracts	6,707	6,704	6,697
Contributions from noncontrolling interests in property partnerships	849	18,002	8,219
Distributions to noncontrolling interests in property partnerships	$ (85,518)	$ (259,764)	$ (58,811)
Accounting Standards Update 2018-09
Accounting Standards Update [Extensible List]				Accounting Standards Update 2014-09 [Member]
General Partner [Member]
Common Stock, Shares, Outstanding	1,750,000	1,746,000	1,731,000	1,727,000
Net activity from contributions and unearned compensation	1,000	5,000	1,000
Conversion of redeemable partnership units	3,000	10,000	3,000
Limited Partner [Member]
Common Stock, Shares, Outstanding	155,008,000	154,799,000	153,988,000	153,063,000
Net activity from contributions and unearned compensation	30,000	295,000	72,000
Conversion of redeemable partnership units	179,000	516,000	853,000
Partners' Capital (General and Limited Partners)[Member]
Beginning Balance	$ 5,299,428	$ 4,173,290	$ 4,554,639	$ 3,380,175
Net activity from contributions and unearned compensation, value	8,291	26,614	10,062
Allocated net income for the period	860,485	512,474	882,275
Distributions	(614,412)	(612,461)	(609,852)
Preferred Stock Redemption Charge		(6,412)
Conversion of redeemable partnership units, value	6,539	18,386	29,689
Adjustment to reflect redeemable partnership units at redemption value	865,235	(319,950)	863,795
Partners' Capital (General and Limited Partners)[Member] \| Cumulative Effect, Period of Adoption, Adjustment
Beginning Balance				(1,505)
Preferred Units [Member]
Beginning Balance	0	0	193,623	193,623
Allocated net income for the period		2,560	10,500
Distributions		(2,560)	(10,500)
Preferred Units [Member] \| Boston Properties Limited Partnership
Preferred Stock, Redemption Amount		(193,623)
Accumulated Other Comprehensive Loss [Member]
Beginning Balance	(13,718)	(36,662)	(49,890)	(48,335)
Effective portion of interest rate contracts	17,435	7,703	(7,066)
Amortization of interest rate contracts	5,509	5,525	5,511
Noncontrolling interest - property partnerships [Member]
Beginning Balance	1,547,317	1,556,553	1,726,933	1,728,689
Allocated net income for the period	74,857	70,806	48,260
Amortization of interest rate contracts	576	576	576
Contributions from noncontrolling interests in property partnerships	849	18,002	8,219
Distributions to noncontrolling interests in property partnerships	(85,518)	(259,764)	(58,811)
Total Capital [Member]
Beginning Balance	6,833,027	5,693,181	6,425,305	5,254,152
Net activity from contributions and unearned compensation, value	8,291	26,614	10,062
Allocated net income for the period	935,342	585,840	941,035
Distributions	(614,412)	(615,021)	(620,352)
Preferred Stock, Redemption Amount		(193,623)
Preferred Stock Redemption Charge		(6,412)
Conversion of redeemable partnership units, value	6,539	18,386	29,689
Adjustment to reflect redeemable partnership units at redemption value	865,235	(319,950)	863,795
Effective portion of interest rate contracts	17,435	7,703	(7,066)
Amortization of interest rate contracts	6,085	6,101	6,087
Contributions from noncontrolling interests in property partnerships	849	18,002	8,219
Distributions to noncontrolling interests in property partnerships	(85,518)	(259,764)	(58,811)
Total Capital [Member] \| Cumulative Effect, Period of Adoption, Adjustment
Beginning Balance				(1,505)
Noncontrolling interest - Redeemable partnership units [Member]
Beginning Balance	1,280,886	2,078,603	1,643,024	2,468,753
Net activity from contributions and unearned compensation, value	46,408	45,773	39,318
Allocated net income for the period	96,780	55,931	97,704
Distributions	(71,714)	(68,822)	(68,921)
Issuance of operating partnership units for 360 Park Avenue South		99,689
Conversion of redeemable partnership units, value	(6,539)	(18,386)	(29,689)
Adjustment to reflect redeemable partnership units at redemption value	(865,235)	319,950	(863,795)
Effective portion of interest rate contracts	1,961	841	(782)
Amortization of interest rate contracts	$ 622	$ 603	$ 610
Noncontrolling interest - Redeemable partnership units [Member] \| Cumulative Effect, Period of Adoption, Adjustment
Beginning Balance				$ (174)

Subsequent Events (Details) $ in Thousands						12 Months Ended
Subsequent Events (Details) $ in Thousands	Feb. 07, 2023 shares	Feb. 03, 2023 USD ($) shares	Jan. 31, 2023 USD ($) ft² a	Jan. 04, 2023 USD ($)	Dec. 31, 2022 ft² shares	Dec. 31, 2022 ft² shares	Dec. 31, 2021 shares	Dec. 31, 2020 shares	Jan. 30, 2023 ft²	Jan. 25, 2023 USD ($) shares	Jan. 05, 2023 ft²	Sep. 08, 2022 ft²	Jun. 15, 2021 USD ($)
Subsequent Event [Line Items]
Line of Credit, Additional Borrowing Capacity \| $													$ 500,000
Debt Instrument, Basis Spread on Variable Rate					0.775%
Common stock, shares issued					156,836,767	156,836,767	156,623,749
Restricted Stock [Member]
Subsequent Event [Line Items]
Common stock, shares issued					41,818	41,818	57,383	29,630
Boston Properties Limited Partnership \| LTIP Units [Member]
Subsequent Event [Line Items]
Number of shares issued						280,616	281,640	207,181
Construction in Progress
Subsequent Event [Line Items]
Net Rentable Area (in sf) \| ft²					3,200,000	3,200,000
300 Binney Street
Subsequent Event [Line Items]
Net Rentable Area (in sf) \| ft²												195,000
300 Binney Street \| Construction in Progress
Subsequent Event [Line Items]
Net Rentable Area (in sf) \| ft²												240,000
Subsequent Event [Member] \| 2023 Unsecured Term Loan
Subsequent Event [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity \| $				$ 1,200,000
Line of Credit, Additional Borrowing Capacity \| $				$ 300,000
Number of extensions				1
Extension Option (in months)				12
Proceeds from Unsecured Lines of Credit \| $				$ 1,200,000
Debt Instrument, Interest Rate Terms				At BPLP’s option, loans under the 2023 Unsecured Term Loan will bear interest at a rate per annum equal to (1) a base rate equal to the greatest of (a) the Federal Funds rate plus 1/2 of 1%, (b) the administrative agent’s prime rate, (c) Term SOFR for a one-month period plus 1.00%, and (d) 1.00%, in each case, plus a margin ranging from 0 to 60 basis points based on BPLP’s credit rating; or (2) a rate equal to adjusted Term SOFR with a one-month period plus a margin ranging from 75 to 160 basis points based on BPLP’s credit rating.
Subsequent Event [Member] \| 2023 Unsecured Term Loan \| Base Rate [Member]
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate				0.00%
Subsequent Event [Member] \| 2023 Unsecured Term Loan \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate				0.85%
Subsequent Event [Member] \| Minimum [Member] \| 2023 Unsecured Term Loan
Subsequent Event [Line Items]
Number of Additional Term Loans				1
Subsequent Event [Member] \| Restricted Stock [Member]
Subsequent Event [Line Items]
Common stock, shares issued		64,731
Subsequent Event [Member] \| MYLTIP 2023
Subsequent Event [Line Items]
Value of MYLTIP Awards \| $										$ 13,100
Subsequent Event [Member] \| MYLTIP 2023 \| Minimum [Member]
Subsequent Event [Line Items]
Common stock available for issuance										0
Subsequent Event [Member] \| MYLTIP 2023 \| Maximum [Member]
Subsequent Event [Line Items]
Common stock available for issuance										322,053
Subsequent Event [Member] \| MYLTIP 2023 \| Target
Subsequent Event [Line Items]
Common stock available for issuance										161,026
Subsequent Event [Member] \| MYLTIP 2020 [Member]
Subsequent Event [Line Items]
Final awards percentage of target		50.00%
Value of MYLTIP Awards \| $		$ 3,800
Forfeitures, in units		152,460
Subsequent Event [Member] \| Boston Properties Limited Partnership \| LTIP Units [Member]
Subsequent Event [Line Items]
Number of shares issued	401,543
Subsequent Event [Member] \| 290 Binney \| Construction in Progress
Subsequent Event [Line Items]
Net Rentable Area (in sf) \| ft²											566,000
Leased percentage											100.00%
Subsequent Event [Member] \| 300 Binney Street
Subsequent Event [Line Items]
Net Rentable Area (in sf) \| ft²									195,000
Subsequent Event [Member] \| 300 Binney Street \| Construction in Progress
Subsequent Event [Line Items]
Net Rentable Area (in sf) \| ft²									240,000
Leased percentage									100.00%
Subsequent Event [Member] \| Worldgate Drive
Subsequent Event [Line Items]
Net Rentable Area (in sf) \| ft²			350,000
Payments to Acquire Interest in Joint Venture \| $			$ 17,000
Ownership Percentage			50.00%
Number of buildings			2
Number of parking space			1,200
Area of Land \| a			10

2021 Credit Facility and 2022 Unsecured Term Loan Compliance (Details) - 2021 Credit Facility and 2022 Unsecured Term Loan	12 Months Ended
	Dec. 31, 2022
Debt Instrument [Line Items]
Debt Instrument, Covenant Description	The 2021 Credit Facility and 2022 Unsecured Term Loan contain customary representations and warranties, affirmative and negative covenants and events of default provisions, including the failure to pay indebtedness, breaches of covenants and bankruptcy and other insolvency events, which could result in the acceleration of the obligation to repay, in the case of the 2021 Credit Facility, all outstanding amounts and the cancellation of all commitments outstanding under the 2021 Credit Facility and, in the case of the 2022 Unsecured Term Loan, any outstanding amount under the 2022 Unsecured Term Loan. Among other covenants, the 2021 Credit Facility and the 2022 Unsecured Term Loan require that BPLP maintain on an ongoing basis: (1) a leverage ratio not to exceed 60%, however, the leverage ratio may increase to no greater than 65% provided that it is reduced back to 60% within one year, (2) a secured debt leverage ratio not to exceed 55%, (3) a fixed charge coverage ratio of at least 1.40, (4) an unsecured debt leverage ratio not to exceed 60%, however, the unsecured debt leverage ratio may increase to no greater than 65% provided that it is reduced to 60% within one year, (5) an unsecured debt interest coverage ratio of at least 1.75 and (6) limitations on permitted investments.
Leverage ratio	60.00%
Leverage ratio - maximum	65.00%
Secured debt leverage ratio - maximum	55.00%
Fixed charge coverage - minimum	1.40
Unsecured debt leverage ratio	60.00%
Unsecured debt leverage ratio - maximum	65.00%
Unsecured debt interest coverage ratio	1.75
Debt Instrument, Covenant Compliance	At December 31, 2022, BPLP was in compliance with each of these financial and other covenant requirements.

Summary Of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Real Estate

Depreciation is computed on a straight-line basis over the estimated useful lives of the assets as follows:


Land improvements						25 to 40 years
Buildings and improvements						10 to 40 years
Tenant improvements						Shorter of useful life or terms of related lease
Furniture, fixtures, and equipment						3 to 7 years

Cash and Cash Equivalents

Cash and Cash Equivalents Cash and cash equivalents consist of cash on hand and investments with maturities of three months or less from the date of purchase. The majority of the Company’s cash and cash equivalents are held at major commercial banks which may at times exceed the Federal Deposit Insurance Corporation limit of $250,000.

Cash Held in Escrows

Cash Held in EscrowsEscrows include amounts established pursuant to various agreements for security deposits, property taxes, insurance and other costs. Escrows also include cash held by qualified intermediaries for possible investments in like-kind exchanges in accordance with Section 1031 of the Internal Revenue Code, as amended (the “Code”), in connection with sales of the Company’s properties.

Investment in Securities

Investments in Securities The Company accounts for investments in equity securities at fair value, with gains or losses resulting from changes in fair value recognized currently in earnings. The Company maintains deferred compensation plans that are designed to allow officers and non-employee directors of BXP to defer a portion of the officer’s current income or the non-employee director’s current compensation on a pre-tax basis and receive a tax-deferred return on these deferrals based on the performance of specific investments selected by the officer or non-employee director. The Company’s obligation under the plans is that of an unsecured promise to pay the deferred compensation to the plan participants in the future.

Tenant and Other Receivables and Notes Receivable

Tenant and Other Receivables

Tenant and other accounts receivable, other than accrued rents receivable, are expected to be collected within one year.

Notes Receivable

Deferred Charges

Non-Real Estate Investments

Non-Real Estate InvestmentsThe Company measures its investments in non-real estate investments, which are primarily environmentally focused investment funds, at the readily determinable fair value of the investment. Changes in the fair value of these non-real estate investments are included in unrealized gain (loss) on non-real estate investments on the Consolidated Statements of Operations. The Company’s investment in non-real estate investments is shown within Prepaid and Other Assets in the Consolidated Balance Sheet. The Company recognized a net unrealized loss of approximately $0.2 million for the year ended December 31, 2022 due to the observable changes in fair value. Prior to the year ended December 31, 2022, the Company had not invested in non-real estate investments.

Investments in Unconsolidated Joint Ventures

the Company consolidates entities in which the outside partner has no substantive kick-out rights to remove the Company as the managing member.

The combined summarized financial information of the unconsolidated joint ventures is disclosed in Note 6.

Revenue Recognition


	Acquired Above-Market Lease Intangibles		Acquired Below-Market Lease Intangibles
2023	$	1,306	$	13,439
2024	401		9,811
2025	389		9,768
2026	389		8,647
2027	389		5,477

Lessee, Leases

Lessee

•observable mortgage rates spread over U.S. Treasury issuances, and

•unlevered property yields and discount rates.

The Company then applied adjustments to account for considerations related to term and interpolated the IBR.

Lessor, Leases

Lessor

Operating Leases

policy election to account for and present the lease component and the nonlease component as a single component in the revenue section of the Consolidated Statements of Operations labeled Lease.

Recoveries from tenants, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized as revenue in the period during which the expenses are incurred. The Company recognizes these reimbursements on a gross basis, as the Company obtains control of the goods and services before they are transferred to the tenant.

In addition, in accordance with ASC 842, lessors will only capitalize incremental direct leasing costs.

Sales-Type Leases

Earnings Per Share and Earnings Per Common Unit

Earnings Per Share

Earnings Per Common Unit

Recurring Fair Value of Financial Instruments


Financial Instrument			Level
Unsecured senior notes (1)			Level 1
Related party note receivable			Level 3
Notes receivable			Level 3
Sales-type lease receivable			Level 3
Mortgage notes payable			Level 3
Unsecured line of credit			Level 3
Unsecured term loan			Level 3

_______________

(1)If trading volume for the period is low, the valuation could be categorized as Level 2.


	December 31, 2022				December 31, 2021
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Related party note receivable, net	$	78,576	$	79,220	$	78,336	$	82,867
Note receivable, net	—		—		9,641		10,000
Sales-type lease receivable, net	12,811		13,045		—		—
Total	$	91,387	$	92,265	$	87,977	$	92,867

Mortgage notes payable, net	$	3,272,368	$	2,744,479	$	3,267,914	$	3,395,569
Unsecured senior notes, net	10,237,968		9,135,512		9,483,695		9,966,591
Unsecured line of credit	—		—		145,000		145,317
Unsecured term loan, net	730,000		730,000		—		—
Total	$	14,240,336	$	12,609,991	$	12,896,609	$	13,507,477

Derivative Instruments and Hedging Activities

Stock-Based Employee Compensation Plans

Stock-Based Employee Compensation PlansAt December 31, 2022, the Company had a stock-based employee compensation plan. The Company accounts for the plan under the guidance in ASC 718 “Compensation – Stock Compensation” (“ASC 718”), which revised the fair value based method of accounting for share-based payment liabilities, forfeitures and modifications of stock-based awards and clarified previous guidance in several areas, including measuring fair value, classifying an award as equity or as a liability and attributing compensation cost to reporting periods.

Use of Estimates in the Preparation of Financial Statements

Equity Offering Costs

Equity Offering Costs Underwriting commissions and offering costs have been reflected as a reduction of additional paid-in capital.

Treasury Stock

Treasury Stock BXP’s share repurchases are reflected as treasury stock utilizing the cost method of accounting and are presented as a reduction to consolidated stockholders’ equity.

Dividends

Dividends Earnings and profits, which determine the taxability of dividends to stockholders, will differ from income reported for financial reporting purposes due to the differences for federal income tax purposes in the treatment of gains/losses on the sale of real property, revenue and expense recognition, compensation expense, and in the estimated useful lives and basis used to compute depreciation.

Income Taxes

BPLP

Income Taxes

Stockholders' Equity / Partners' Capital Dividends / Distributions (Details) - $ / shares	Oct. 31, 2022	Jul. 29, 2022	Apr. 29, 2022	Jan. 28, 2022	Oct. 29, 2021	Jul. 30, 2021	Apr. 30, 2021	Feb. 16, 2021	Jan. 28, 2021	Nov. 16, 2020	Oct. 30, 2020	Aug. 17, 2020	Jul. 31, 2020	May 15, 2020	Apr. 30, 2020	Feb. 18, 2020	Jan. 30, 2020	Dec. 19, 2022
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit																		$ 0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98		$ 0.98		$ 0.98		$ 0.98		$ 0.98		$ 0.98
Boston Properties Limited Partnership
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit																		0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	0.98	0.98	0.98	0.98	0.98	0.98	0.98		0.98		0.98		0.98		0.98		0.98
Boston Properties Limited Partnership \| Op units and LTIP units
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit																		0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	0.98	0.98	0.98	0.98	0.98	0.98	0.98		0.98		0.98		0.98		0.98		0.98
Boston Properties Limited Partnership \| Unvested MYLTIP Units [Member]
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit																		$ 0.098
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098		$ 0.098		$ 0.098		$ 0.098		$ 0.098		$ 0.098
Series B Cumulative Redeemable Preferred Stock / Unit [Member]
Dividends / Distributions [Line Items]
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid								$ 32.8125		$ 32.8125		$ 32.8125		$ 32.8125		$ 32.8125

Real Estate (Narrative) (Details) $ in Thousands													3 Months Ended	4 Months Ended	5 Months Ended	7 Months Ended	8 Months Ended	10 Months Ended	12 Months Ended
Real Estate (Narrative) (Details) $ in Thousands	Nov. 08, 2022 USD ($) ft² floor	Oct. 19, 2022 ft² Building	Sep. 16, 2022 USD ($) ft²	Sep. 15, 2022 USD ($) land_parcel	Aug. 30, 2022 USD ($) ft²	Jul. 01, 2022 ft² Building	Jun. 15, 2022 USD ($) ft² Building	May 17, 2022 USD ($) ft² floor	Apr. 27, 2022 ft² Building	Apr. 07, 2022 USD ($)	Mar. 31, 2022 USD ($) ft²	Apr. 19, 2021 USD ($) ft² a	Mar. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) ft²	Jun. 14, 2022 USD ($)	Dec. 31, 2022 USD ($) ft²	Aug. 29, 2022 USD ($)	Nov. 07, 2022 USD ($)	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 23, 2022 ft²	Dec. 01, 2022 ft²	Nov. 30, 2022 ft²	Sep. 12, 2022 ft²	Sep. 08, 2022 ft²	Jun. 29, 2022 ft²	May 13, 2022 ft²	Apr. 29, 2022 ft²	May 09, 2019 ft²
Real Estate Properties [Line Items]
Unsecured term loan								$ 730,000						$ 730,000		$ 730,000			$ 730,000	$ 0
Total revenue																			3,108,581	2,888,621	$ 2,765,686
Net income																			1,020,584	631,932	1,018,691
Proceeds from sales of real estate																			834,770	179,887	519,303
Interest and Other Income																			11,940	5,704	5,953
Other income - assignment fee																			$ 6,624	0	0
Construction in Progress
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²														3,200,000		3,200,000			3,200,000
Boston Properties Limited Partnership
Real Estate Properties [Line Items]
Unsecured term loan														$ 730,000		$ 730,000			$ 730,000	0
Total revenue																			3,108,581	2,888,621	2,765,686
Net income																			1,032,122	641,771	1,038,739
Proceeds from sales of real estate																			834,770	179,887	519,303
Interest and Other Income																			11,940	5,704	5,953
Other income - assignment fee																			$ 6,624	0	0
Madison Centre
Real Estate Properties [Line Items]
Noncash or Part Noncash Acquisition, Value of Assets Acquired								$ 724,300
Net Rentable Area (in sf) \| ft²								755,000
Number of floors \| floor								37
Total revenue																32,000
Net income																$ 2,100
125 Broadway
Real Estate Properties [Line Items]
Payments to Acquire Real Estate			$ 592,400
Net Rentable Area (in sf) \| ft²			271,000
Total revenue														11,400
Net income														$ 3,300
195 West Street
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²											63,500
Net income													$ 400							500	(800)
Contractual Sales Price											$ 37,700
Proceeds from sales of real estate											35,400
Gains (Losses) on Sales of Investment Real Estate											22,700
195 West Street \| Boston Properties Limited Partnership
Real Estate Properties [Line Items]
Gains (Losses) on Sales of Investment Real Estate											$ 23,400
11251 Roger Bacon Drive
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²												65,000
Asset Acquisition, Price of Acquisition, Expected												$ 5,600
Interest and Other Income										$ 6,900
Other income - assignment fee										$ 6,600
Area of Land \| a												2.6
Virginia 95 Office Park
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²							733,000
Net income															$ 2,300					7,000	7,800
Contractual Sales Price							$ 127,500
Proceeds from sales of real estate							121,900
Gains (Losses) on Sales of Investment Real Estate							$ 96,200
Number of buildings \| Building							11
Virginia 95 Office Park \| Boston Properties Limited Partnership
Real Estate Properties [Line Items]
Gains (Losses) on Sales of Investment Real Estate							$ 99,500
601 Massachusetts Avenue
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²					479,000
Net income																	$ 14,900			22,400	21,800
Contractual Sales Price					$ 531,000
Proceeds from sales of real estate					512,300
Gains (Losses) on Sales of Investment Real Estate					237,400
601 Massachusetts Avenue \| Boston Properties Limited Partnership
Real Estate Properties [Line Items]
Gains (Losses) on Sales of Investment Real Estate					$ 237,500
Loudoun County Land
Real Estate Properties [Line Items]
Contractual Sales Price				$ 27,000
Proceeds from sales of real estate				25,600
Gains (Losses) on Sales of Investment Real Estate				$ 24,400
Parcels of undeveloped land \| land_parcel				2
The Avant at Reston Town Center
Real Estate Properties [Line Items]
Net income																		$ 4,100		$ 4,000	$ 4,000
The Avant at Reston Town Center \| Residential Building
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²	329,000
Number of floors \| floor	15
Contractual Sales Price	$ 141,000
Proceeds from sales of real estate	139,600
Gains (Losses) on Sales of Investment Real Estate	$ 55,600
Number of Units in Real Estate Property	359
The Avant Retail \| Retail Site [Member]
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²	26,000
290 Binney Street
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²									566,000
Lessor, Operating Lease, Lease Not yet Commenced, Description									15-year
Kendall Center future development \| Scenario, Plan
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²									1,100,000
Number of buildings \| Building									2
Kendall Center future development \| Scenario, Plan \| Residential Building
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²									400,000
2100 Pennsylvania Avenue
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																													480,000
Reston Next Office Phase II
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																												90,000
325 Main Street
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																											414,000			115,000
140 Kendrick Street
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²						388,000
Number of buildings \| Building						3
140 Kendrick - Building A
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²						90,000
Number of buildings \| Building						1
140 Kendrick - Building A \| Construction in Progress
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²						104,000
300 Binney Street
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																										195,000
300 Binney Street \| Construction in Progress
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																										240,000
760 Boylston Street [Member] \| Construction in Progress
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																									118,000
Reston Next
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²		1,100,000
Number of buildings \| Building		2
105 Carnegie Center
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																								70,000
105 Carnegie Center \| Construction in Progress
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																								73,000
2096 Gaither Road
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																							50,000
880 Winter Street [Member]
Real Estate Properties [Line Items]
Net Rentable Area (in sf) \| ft²																						244,000

Deferred Charges (Tables)

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Deferred Costs

Deferred charges consisted of the following at December 31, 2022 and 2021 (in thousands):


	December 31, 2022		December 31, 2021
Leasing costs, including lease related intangibles	$	1,095,231	$	1,011,229
Financing costs	19,311		19,231
	1,114,542		1,030,460
Less: Accumulated amortization	(381,260)		(411,662)
	$	733,282	$	618,798

Finite-lived Intangible Assets Amortization Expense

The following table summarizes the scheduled amortization of the Company’s acquired in-place lease intangibles for each of the five succeeding years (in thousands).


	Acquired In-Place Lease Intangibles
2023	$	27,659
2024	21,595
2025	21,419
2026	20,571
2027	18,214

Unsecured Senior Notes (Narrative) (Details) - USD ($)
$ in Thousands

12 Months Ended

Nov. 17, 2022

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Debt Instrument [Line Items]

Proceeds from unsecured senior notes

$ 749,557

$ 1,695,996

$ 1,248,125

Boston Properties Limited Partnership

Debt Instrument [Line Items]

Proceeds from unsecured senior notes

749,557

$ 1,695,996

$ 1,248,125

Senior Notes | Boston Properties Limited Partnership

Debt Instrument [Line Items]

Debt

$ 10,300,000

Debt Instrument, Covenant Description

Leverage ratio

60.00%

Secured debt leverage ratio - maximum

50.00%

Interest Coverage - Maximum

1.50

Unencumbered Asset Value - Minimum

150.00%

Debt Instrument, Covenant Compliance

At December 31, 2022, BPLP was in compliance with each of these financial restrictions and requirements.

6.924% unsecured senior notes | Senior Notes | Boston Properties Limited Partnership

Debt Instrument [Line Items]

Debt

$ 750,000

Debt Instrument, Interest Rate, Stated Percentage

6.75%

Senior Notes Pricing

99.941%

Debt Instrument, Interest Rate, Effective Percentage

6.924%

^[1]

Proceeds from unsecured senior notes

$ 743,500

[1]	Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.

Stockholders' Equity / Partners' Capital

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Stockholders' Equity / Partners' Capital

10. Stockholders’ Equity / Partners’ Capital

BXP

As of December 31, 2022, BXP had 156,757,867 shares of Common Stock outstanding.

As of December 31, 2022, BXP owned 1,749,682 general partnership units and 155,008,185 limited partnership units in BPLP.

On May 22, 2020, BXP renewed its “at the market” (“ATM”) stock offering program through which it may sell from time to time up to an aggregate of $600.0 million of its Common Stock through sales agents over a three-year period. Under the ATM stock offering program, BXP may also engage in forward sale transactions with affiliates of certain sales agents for the sale of its Common Stock on a forward basis. This program replaced BXP’s prior $600.0 million ATM stock offering program that was scheduled to expire on June 2, 2020. BXP intends to use the net proceeds from any offering for general business purposes, which may include investment opportunities and debt reduction. No shares of Common Stock have been issued under this ATM stock offering program.

During the year ended December 31, 2022, BXP did not issue any shares of Common Stock upon the exercise of options to purchase Common Stock. During the year ended December 31, 2021, BXP issued 247,920 shares of Common Stock upon the exercise of options to purchase Common Stock.

During the years ended December 31, 2022 and December 31, 2021, BXP issued 182,929 and 523,969 shares of Common Stock, respectively, in connection with the redemption of an equal number of redeemable OP Units from limited partners.

The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared during the years ended December 31, 2022, 2021 and 2020:


Record Date	Payment Date	Dividend (Per Share)	Distribution (Per Unit)
December 30, 2022	January 30, 2023	$0.98	$0.98
September 30, 2022	October 31, 2022	$0.98	$0.98
June 30, 2022	July 29, 2022	$0.98	$0.98
March 31, 2022	April 29, 2022	$0.98	$0.98
December 31, 2021	January 28, 2022	$0.98	$0.98
September 30, 2021	October 29, 2021	$0.98	$0.98
June 30, 2021	July 30, 2021	$0.98	$0.98
March 31, 2021	April 30, 2021	$0.98	$0.98
December 31, 2020	January 28, 2021	$0.98	$0.98
September 30, 2020	October 30, 2020	$0.98	$0.98
June 30, 2020	July 31, 2020	$0.98	$0.98
March 31, 2020	April 30, 2020	$0.98	$0.98
December 31, 2019	January 30, 2020	$0.98	$0.98

Preferred Stock

At December 31, 2020, BXP had 80,000 shares (8,000,000 Depositary Shares each representing 1/100th of a share) outstanding of its 5.25% Series B Preferred Stock with a liquidation preference of $2,500.00 per share ($25.00 per Depositary Share). BXP paid cumulative cash dividends on the Series B Preferred Stock at a rate of 5.25% per annum of the $2,500.00 liquidation preference per share. BXP did not have the right to redeem the Series B Preferred Stock prior to March 27, 2018, except in certain circumstances relating to the preservation of BXP’s REIT status. On and after March 27, 2018, BXP, at its option, could redeem the Series B Preferred Stock for a cash redemption price of $2,500.00 per share ($25.00 per Depositary Share), plus all accrued and unpaid dividends. The Series B Preferred Stock was not redeemable by the holders, had no maturity date and was not convertible into any other security of BXP or its affiliates.

On March 2, 2021, BXP issued a redemption notice for 80,000 shares of its 5.25% Series B Cumulative Redeemable Preferred Stock, which constituted all of the outstanding Series B Preferred Stock, and the corresponding depositary shares, each representing 1/100th of a share of Series B Preferred Stock. The

redemption price per share of Series B Preferred Stock was $2,500, plus all accrued and unpaid dividends to, but not including, the redemption date, totaling $2,516.41 per share. On March 31, 2021, the Company transferred the full redemption price for all outstanding shares of Series B Preferred Stock of approximately $201.3 million, including approximately $1.3 million of accrued and unpaid dividends to, but not including, the redemption date, to the redemption agent. The excess of the redemption price over the carrying value of the Series B Preferred Stock and Series B Preferred Units of approximately $6.4 million relates to the original issuance costs and is reflected as a reduction to Net Income Attributable to Boston Properties, Inc. Common Shareholders and Net Income Attributable to Boston Properties Limited Partnership Common Unitholders on the Consolidated Income Statements.

On April 1, 2021, BXP redeemed all of the outstanding shares of Series B Preferred Stock and all of the outstanding Depositary Shares. In connection with the redemption of the Series B Preferred Stock, all of the Series B Preferred Units, which had terms and preferences generally mirroring those of the Series B Preferred Stock, were redeemed by BPLP.

The following table presents BXP’s dividend per share on its Series B Preferred Stock paid during the years ended December 31, 2021 and 2020:

Record Date

Payment Date

Dividend (Per Share)

February 5, 2021

February 16, 2021

$32.8125

November 4, 2020

November 16, 2020

$32.8125

August 3, 2020

August 17, 2020

$32.8125

May 1, 2020

May 15, 2020

$32.8125

February 4, 2020

February 18, 2020

$32.8125

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI https://asc.fasb.org/topic&trid=2208762

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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-Subparagraph (h)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126731327&loc=SL126733271-114008

+ Details

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2022
Auditor [Line Items]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	238
Boston Properties Limited Partnership
Auditor [Line Items]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	238

Schedule of Aggregate Principal Payments on Mortgage Notes (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Mortgage notes payable, net	$ 3,272,368	$ 3,267,914
Mortgages [Member]
Debt Instrument [Line Items]
2023	0
2024	0
2025	0
2026	0
2027	2,300,000
Thereafter	1,000,000
Total	3,300,000
Deferred financing costs, net	27,632
Mortgage notes payable, net	$ 3,272,368	$ 3,300,000

Noncontrolling Interests Common Units Distributions (Details) - $ / shares	Oct. 31, 2022	Jul. 29, 2022	Apr. 29, 2022	Jan. 28, 2022	Oct. 29, 2021	Jul. 30, 2021	Apr. 30, 2021	Jan. 28, 2021	Oct. 30, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 30, 2020	Dec. 19, 2022
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit													$ 0.98
Dividends, Per Unit, Cash Paid	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98
Boston Properties Limited Partnership
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit													0.98
Dividends, Per Unit, Cash Paid	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98
Boston Properties Limited Partnership \| Op units and LTIP units
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit													0.98
Dividends, Per Unit, Cash Paid	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98	0.98
Boston Properties Limited Partnership \| Unvested MYLTIP Units [Member]
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit													$ 0.098
Dividends, Per Unit, Cash Paid	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098

Leases (Tables)

12 Months Ended

Dec. 31, 2022

Lessee, Lease, Description [Line Items]

Lease, Cost

The following table provides lease cost information for the Company’s operating and finance leases for the years ended December 31, 2022, 2021 and 2020 (in thousands):


	Year ended December 31,
Lease costs	2022		2021		2020
Operating lease costs	$	12,700	$	13,151	$	13,948
Finance lease costs
Amortization of right of use asset (1)	$	697	$	547	$	56
Interest on lease liabilities (2)	$	3,236	$	2,471	$	583

_______________

The following table provides other quantitative information for the Company’s operating and finance leases as of December 31, 2022 and December 31, 2021:


	December 31, 2022		December 31, 2021
Other information
Weighted-average remaining lease term (in years)
Operating leases	49		50
Finance leases	68		69
Weighted-average discount rate
Operating leases	5.7	%	5.7	%
Finance leases	6.2	%	6.2	%

Finance Lease, Liability, Maturity

The following table provides a maturity analysis for the Company’s lease liabilities related to its operating and finance leases as of December 31, 2022 (in thousands):


	Operating		Finance
2023	$	22,415	$	9,306
2024 (1)	22,274		49,343
2025	10,308		9,971
2026	10,100		10,166
2027	9,885		10,364
Thereafter	528,915		1,352,647
Total lease payments	603,897		1,441,797
Less:
Interest portion	399,211		1,192,462
Present value of lease payments	$	204,686	$	249,335

_______________

(1)Finance lease payments in 2024 include approximately $38.7 million related to a purchase option that the Company is reasonably certain it will exercise.

The following table provides a maturity analysis for the Company’s lease liabilities related to its operating and finance leases as of December 31, 2021 (in thousands):


	Operating		Finance
2022	$	19,623	$	8,762
2023	25,333		10,826
2024 (1)	10,085		48,605
2025	10,307		9,971
2026	10,100		10,166
Thereafter	538,801		1,363,011
Total lease payments	614,249		1,451,341
Less:
Interest portion	409,688		1,206,920
Present value of lease payments	$	204,561	$	244,421

_______________

(1)Finance lease payments in 2024 include approximately $38.7 million related to a purchase option that the Company is reasonably certain it will exercise.

Lessee, Operating Lease, Liability, Maturity

The following table provides a maturity analysis for the Company’s lease liabilities related to its operating and finance leases as of December 31, 2022 (in thousands):


	Operating		Finance
2023	$	22,415	$	9,306
2024 (1)	22,274		49,343
2025	10,308		9,971
2026	10,100		10,166
2027	9,885		10,364
Thereafter	528,915		1,352,647
Total lease payments	603,897		1,441,797
Less:
Interest portion	399,211		1,192,462
Present value of lease payments	$	204,686	$	249,335

_______________

(1)Finance lease payments in 2024 include approximately $38.7 million related to a purchase option that the Company is reasonably certain it will exercise.

The following table provides a maturity analysis for the Company’s lease liabilities related to its operating and finance leases as of December 31, 2021 (in thousands):


	Operating		Finance
2022	$	19,623	$	8,762
2023	25,333		10,826
2024 (1)	10,085		48,605
2025	10,307		9,971
2026	10,100		10,166
Thereafter	538,801		1,363,011
Total lease payments	614,249		1,451,341
Less:
Interest portion	409,688		1,206,920
Present value of lease payments	$	204,561	$	244,421

_______________

(1)Finance lease payments in 2024 include approximately $38.7 million related to a purchase option that the Company is reasonably certain it will exercise.

Lessor, Lease, Description [Line Items]

Operating Lease, Lease Income [Table Text Block]

Lessor

Operating Leases


	Year ended December 31,
Lease Revenue	2022		2021		2020
Fixed contractual payments	$	2,426,007	$	2,319,362	$	2,211,915
Variable lease payments	492,361		433,652		434,346
	$	2,918,368	$	2,753,014	$	2,646,261

Lessor, Operating Lease, Payments to be Received, Maturity


Years Ending December 31,
2023	$	2,338,610
2024	2,321,135
2025	2,279,700
2026	2,212,455
2027	2,094,014
Thereafter	13,020,102

Sales-type and Direct Financing Leases, Lease Receivable, Maturity

The following table provides the future contractual payments to be received as of December 31, 2022 (in thousands):


	Sales-Type
2023	$	—
2024	31
2025	124
2026	372
2027	756
Thereafter	268,249
Total lease payments to be received	269,532
Less:
Interest portion	256,504
Sales-type lease receivable	13,028
Unguaranteed residual asset	17
Current expected credit loss adjustment	(234)
Sales-type lease receivable, net	$	12,811

Investment in Unconsolidated Joint Ventures (Narrative) (Details)
$ in Thousands

1 Months Ended

4 Months Ended

12 Months Ended

Dec. 31, 2022

USD ($)

Dec. 23, 2022

ft²

loanExtension

Dec. 22, 2022

USD ($)

loanExtension

Dec. 07, 2022

ft²

Dec. 06, 2022

USD ($)

loanExtension

Nov. 17, 2022

USD ($)

ft²

floor

Sep. 09, 2022

USD ($)

ft²

Sep. 08, 2022

USD ($)

Sep. 01, 2022

USD ($)

ft²

Aug. 08, 2022

USD ($)

ft²

Aug. 07, 2022

USD ($)

Jun. 17, 2022

USD ($)

Jun. 16, 2022

USD ($)

ft²

May 13, 2022

USD ($)

loanExtension

years

Apr. 18, 2022

USD ($)

ft²

Mar. 28, 2022

USD ($)

loanExtension

years

Mar. 27, 2022

USD ($)

loanExtension

years

Dec. 31, 2022

USD ($)

Sep. 06, 2023

Sep. 05, 2023

Apr. 30, 2023

Dec. 31, 2022

USD ($)

Dec. 31, 2021

USD ($)

Dec. 31, 2020

USD ($)

Feb. 02, 2022

ft²

Jan. 18, 2022

ft²

Schedule of Equity Method Investments [Line Items]

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 3,272,368

$ 3,267,914

Debt Instrument, Basis Spread on Variable Rate

0.775%

Payment for Debt Extinguishment or Debt Prepayment Cost

43,036

$ 0

Losses from early extinguishment of debt

(45,182)

Payments to Acquire Equity Method Investments

277,581

98,152

172,436

Assumption of mortgage notes payable

$ 0

200,311

Gateway Commons Complex [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

^[1]

50.00%

Gateway Commons Complex [Member] | 651 Gateway | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Platform 16

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

^[2]

55.00%

Platform 16 | Platform 16 | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

55.00%

Net Rentable Area (in sf) | ft²

1,100,000

BP/CRF Metropolitan Square LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

20.00%

BP/CRF Metropolitan Square LLC [Member] | Metropolitan Square | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

20.00%

Net Rentable Area (in sf) | ft²

657,000

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 420,000

$ 294,100

Debt Instrument, Description of Variable Rate Basis

the greater of (x) LIBOR or (y) 0.65%

Debt Instrument, Basis Spread on Variable Rate

2.75%

4.75%

Number of extensions | loanExtension

Extension Option (in years) | years

Payment for Debt Extinguishment or Debt Prepayment Cost

$ 0

Losses from early extinguishment of debt

(1,300)

Proceeds from mortgage notes payable

100,500

BP/CRF Metropolitan Square LLC [Member] | Metropolitan Square | Unconsolidated Properties | Interest Rate Cap

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Description of Variable Rate Basis

SOFR

Derivative, Notional Amount

$ 420,000

Derivative, Cap Interest Rate

4.50%

Residential Tower Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Residential Tower Developer LLC [Member] | Hub50House [Member] | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Proceeds from mortgage notes payable

$ 6,800

Residential Tower Developer LLC [Member] | Hub50House [Member] | Unconsolidated Properties | Interest Rate Swap

Schedule of Equity Method Investments [Line Items]

Derivative, Notional Amount

$ 185,000

Derivative, Forward Interest Rate

4.432%

Residential Tower Developer LLC [Member] | Hub50House [Member] | Unconsolidated Properties | Adjustable Rate Loans

Schedule of Equity Method Investments [Line Items]

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 185,000

$ 176,700

$ 176,500

Debt Instrument, Basis Spread on Variable Rate

1.35%

2.00%

PR II BXP Reston Gateway LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

^[3]

20.00%

751 Gateway Holdings LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

^[1]

49.00%

BNY Tower Holdings LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

^[4]

50.00%

BNY Tower Holdings LLC [Member] | Dock 72 [Member] | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Net Rentable Area (in sf) | ft²

669,000

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 198,400

Debt Instrument, Description of Variable Rate Basis

the greater of (x) SOFR or (y) 0.25%

LIBOR

Debt Instrument, Basis Spread on Variable Rate

2.50%

3.10%

3.35%

Debt Instrument, Interest Rate, Stated Percentage

0.25%

Debt instrument, borrowing capacity

$ 250,000

Impairment loss on investment

$ 50,700

Capitalization Rate

5.75%

Investment in Unconsolidated Joint Venture, Measurement Input

7.00%

Equity Method Investment, impairment information

The Company determined that its valuation of the investment was categorized within Level 3 of the fair value hierarchy, as it utilized significant unobservable inputs in its assessment including an exit capitalization rate of 5.75%, a discount rate on the Company’s equity investment (the property is encumbered by mortgage debt) of 7.0% and leasing the currently available space over the period of 2023-2026.

Safeco Plaza REIT LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

^[5]

33.67%

Safeco Plaza REIT LLC | Safeco Plaza | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

33.67%

Net Rentable Area (in sf) | ft²

765,000

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 250,000

Debt Instrument, Description of Variable Rate Basis

the greater of (x) 2.35% or (y) SOFR

the greater of (x) 2.35% or (y) LIBOR

Debt Instrument, Basis Spread on Variable Rate

2.32%

2.20%

Safeco Plaza REIT LLC | Safeco Plaza | Unconsolidated Properties | Minimum [Member]

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.35%

Safeco Plaza REIT LLC | Safeco Plaza | Unconsolidated Properties | Interest Rate Cap

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Description of Variable Rate Basis

SOFR

Derivative, Notional Amount

$ 250,000

Derivative, Cap Interest Rate

2.50%

200 Fifth Avenue JV LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

26.69%

200 Fifth Avenue JV LLC | 200 Fifth Avenue | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

26.69%

Net Rentable Area (in sf) | ft²

855,000

Debt Instrument, Basis Spread on Variable Rate

1.30%

Noncash or Part Noncash Acquisition, Value of Assets Acquired

$ 280,200

Payments to Acquire Equity Method Investments

120,100

Assumption of mortgage notes payable

$ 160,100

Number of floors | floor

200 Fifth Avenue JV LLC | 200 Fifth Avenue | Unconsolidated Properties | Interest Rate Swap

Schedule of Equity Method Investments [Line Items]

Derivative, Notional Amount

$ 600,000

Derivative, Forward Interest Rate

4.34%

Square 407 Limited Partnership [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Square 407 Limited Partnership [Member] | Market Square North | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Net Rentable Area (in sf) | ft²

418,000

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 125,000

Debt Instrument, Description of Variable Rate Basis

the greater of (1) the sum of (x) the “benchmark rate”, (y) 2.30% and (z) the adjustment applicable to such “benchmark rate” (approximately 0.11% for Term SOFR), or (2) 2.80%

the greater of (x) LIBOR or (y) 0.50%,

Debt Instrument, Basis Spread on Variable Rate

2.30%

Number of extensions | loanExtension

Extension Option (in years)

Square 407 Limited Partnership [Member] | Market Square North | Unconsolidated Properties | Minimum [Member]

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.80%

Podium Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Joint Venture Partner [Member] | PR II BXP Reston Gateway LLC | Reston Next Residential | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Payments to Acquire Interest in Joint Venture

$ 500

Joint Venture Partner [Member] | PR II BXP Reston Gateway LLC | Reston Next Residential | Unconsolidated Properties | Scenario, Plan

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

80.00%

Payments to Acquire Interest in Joint Venture

$ 58,700

Joint Venture Partner [Member] | 751 Gateway Holdings LLC | 751 Gateway | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

51.00%

Contribution of Property

$ 53,900

Payments to Acquire Interest in Joint Venture

$ 4,900

Unconsolidated Joint Ventures [Member]

Schedule of Equity Method Investments [Line Items]

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 4,022,746

3,214,961

Losses from early extinguishment of debt

(1,327)

Impairment loss on investment

$ (50,705)

^[6]

$ 0

$ (60,524)

^[6]

Unconsolidated Joint Ventures [Member] | PR II BXP Reston Gateway LLC | Reston Next Residential | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Contribution of Property

11,300

Unconsolidated Joint Ventures [Member] | PR II BXP Reston Gateway LLC | Reston Next Residential | Unconsolidated Properties | Scenario, Plan

Schedule of Equity Method Investments [Line Items]

Payments to Acquire Interest in Joint Venture

$ 3,500

Unconsolidated Joint Ventures [Member] | PR II BXP Reston Gateway LLC | Reston Next Residential | Unconsolidated Properties | Adjustable Rate Loans

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Description of Variable Rate Basis

SOFR

Debt Instrument, Basis Spread on Variable Rate

2.00%

Number of extensions | loanExtension

Extension Option (in years) | years

Debt Instrument, Unused Borrowing Capacity, Amount

$ 140,000

Unconsolidated Joint Ventures [Member] | 751 Gateway Holdings LLC | 751 Gateway | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

49.00%

Contribution of Property

$ 53,900

Payments to Acquire Interest in Joint Venture

$ 2,600

Unconsolidated Joint Ventures [Member] | Podium Developer LLC [Member] | The Hub on Causeway - Podium | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Net Rentable Area (in sf) | ft²

380,000

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 174,300

Unconsolidated Joint Ventures [Member] | Podium Developer LLC [Member] | The Hub on Causeway - Podium | Unconsolidated Properties | London Interbank Offered Rate (LIBOR)

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Basis Spread on Variable Rate

2.25%

Unconsolidated Joint Ventures [Member] | Podium Developer LLC [Member] | The Hub on Causeway - Podium | Unconsolidated Properties | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Basis Spread on Variable Rate

2.35%

Unconsolidated Joint Ventures [Member] | Office Tower Developer LLC | 100 Causeway Street [Member] | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Net Rentable Area (in sf) | ft²

630,000

Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)

$ 337,600

Number of extensions | loanExtension

Extension Option (in years)

Unconsolidated Joint Ventures [Member] | Office Tower Developer LLC | 100 Causeway Street [Member] | Unconsolidated Properties | London Interbank Offered Rate (LIBOR)

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Basis Spread on Variable Rate

1.50%

Unconsolidated Joint Ventures [Member] | Office Tower Developer LLC | 100 Causeway Street [Member] | Unconsolidated Properties | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Basis Spread on Variable Rate

1.60%

Company's Share [Member] | BP/CRF Metropolitan Square LLC [Member] | Metropolitan Square

Schedule of Equity Method Investments [Line Items]

Proceeds from mortgage notes payable

$ 20,100

Company's Share [Member] | Residential Tower Developer LLC [Member] | Hub50House [Member] | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Proceeds from mortgage notes payable

$ 3,400

Company's Share [Member] | PR II BXP Reston Gateway LLC | Reston Next Residential | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

96.00%

Company's Share [Member] | PR II BXP Reston Gateway LLC | Reston Next Residential | Unconsolidated Properties | Scenario, Plan

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

20.00%

Construction | Gateway Commons Complex [Member] | 651 Gateway | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Net Rentable Area (in sf) | ft²

327,000

Construction | Platform 16 | Platform 16 | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Net Rentable Area (in sf) | ft²

390,000

Construction | 751 Gateway Holdings LLC | 751 Gateway | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Net Rentable Area (in sf) | ft²

231,000

Schedule of Equity Method Investments [Line Items]

Number of Units in Real Estate Property

508

Residential Building | Residential Tower Developer LLC [Member] | Hub50House [Member] | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Net Rentable Area (in sf) | ft²

320,000

Number of Units in Real Estate Property

440

[1]	On June 16, 2022, in accordance with the Gateway Commons joint venture agreement, 751 Gateway was segregated into a new single-purpose joint venture.
[2]	This entity is a VIE (See Note 2).
[3]	The Company’s partner will fund required capital until its aggregate investment is approximately 80% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.
[4]	This property includes net equity balances from the amenity joint venture.
[5]	The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture.
[6]	During the years ended December 31, 2022 and December 31, 2020, the Company recognized an other-than-temporary impairment loss on its investment in the unconsolidated joint venture that owns Dock 72 in Brooklyn, New York totaling approximately $50.7 million and $60.5 million, respectively.

Real Estate Amortization of Finite Lived Intangible Assets by Major Class (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Sep. 16, 2022
Acquired Finite-Lived Intangible Assets [Line Items]
2023	$ 27,659
2024	21,595
2025	21,419
2026	20,571
2027	18,214
Above Market Lease Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2023	1,306
2024	401
2025	389
2026	389
2027	$ 389
Madison Centre and 125 Broadway \| In-Place Lease Intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
2023		$ 20,940
2024		19,582
2025		19,510
2026		19,046
2027		17,901
Madison Centre and 125 Broadway \| Above Market Lease Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2023		1,098
2024		254
2025		254
2026		254
2027		254
Madison Centre and 125 Broadway \| Below Market Lease Intangible [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2023		6,417
2024		6,386
2025		6,373
2026		6,185
2027		$ 5,780

Segment Information

12 Months Ended

Dec. 31, 2022

Segment Reporting [Abstract]

Segment Reporting Disclosure [Text Block]

11. Segment Information

The following tables present reconciliations of Net Income Attributable to Boston Properties, Inc. Common Shareholders to the Company’s share of Net Operating Income and Net Income Attributable to Boston Properties Limited Partnership Common Unitholders to the Company’s share of Net Operating Income for the years ended December 31, 2022, 2021 and 2020.

BXP


	Year ended December 31,
		2022		2021		2020
		(in thousands)
Net income attributable to Boston Properties, Inc. common shareholders		$	848,947	$	496,223	$	862,227
Add:
Preferred stock redemption charge		—		6,412		—
Preferred dividends		—		2,560		10,500
Noncontrolling interest—common units of the Operating Partnership		96,780		55,931		97,704
Noncontrolling interests in property partnerships		74,857		70,806		48,260
Interest expense		437,139		423,346		431,717
Losses from early extinguishment of debt		—		45,182		—
Unrealized loss on non-real estate investment		150		—		—
Net operating income from unconsolidated joint ventures		146,081		107,756		94,943
Loss from unconsolidated joint ventures		59,840		2,570		85,110
Depreciation and amortization expense		749,775		717,336		683,751
Transaction costs		2,905		5,036		1,531
Payroll and related costs from management services contracts		15,450		12,487		11,626
General and administrative expense		146,378		151,573		133,112
Less:
Net operating income attributable to noncontrolling interests in property partnerships		191,812		186,304		162,887
Gains (losses) from investments in securities		(6,453)		5,626		5,261
Other income - assignment fee		6,624		—		—
Interest and other income (loss)		11,940		5,704		5,953
Gain on sales-type lease		10,058		—		—
Gains on sales of real estate		437,019		123,660		618,982
Direct reimbursements of payroll and related costs from management services contracts		15,450		12,487		11,626
Development and management services revenue		28,056		27,697		29,641
Company’s share of Net Operating Income		$	1,883,796	$	1,735,740	$	1,626,131

BPLP


	Year ended December 31,
		2022		2021		2020
		(in thousands)
Net income attributable to Boston Properties Limited Partnership common unitholders		$	957,265	$	561,993	$	979,979
Add:
Preferred unit redemption charge		—		6,412		—
Preferred distributions		—		2,560		10,500
Noncontrolling interests in property partnerships		74,857		70,806		48,260
Interest expense		437,139		423,346		431,717
Losses from early extinguishment of debt		—		45,182		—
Unrealized loss on non-real estate investment		150		—		—
Net operating income from unconsolidated joint ventures		146,081		107,756		94,943
Loss from unconsolidated joint ventures		59,840		2,570		85,110
Depreciation and amortization expense		742,293		709,035		676,666
Transaction costs		2,905		5,036		1,531
Payroll and related costs from management services contracts		15,450		12,487		11,626
General and administrative expense		146,378		151,573		133,112
Less:
Net operating income attributable to noncontrolling interests in property partnerships		191,812		186,304		162,887
Gains (losses) from investments in securities		(6,453)		5,626		5,261
Other income - assignment fee		6,624		—		—
Interest and other income (loss)		11,940		5,704		5,953
Gain on sales-type lease		10,058		—		—
Gains on sales of real estate		441,075		125,198		631,945
Direct reimbursements of payroll and related costs from management services contracts		15,450		12,487		11,626
Development and management services revenue		28,056		27,697		29,641
Company’s share of Net Operating Income		$	1,883,796	$	1,735,740	$	1,626,131

Net operating income (“NOI”) is a non-GAAP financial measure equal to net income attributable to Boston Properties, Inc. common shareholders and net income attributable to Boston Properties Limited Partnership common unitholders, as applicable, the most directly comparable GAAP financial measures, plus (1) preferred stock/unit redemption charge, preferred dividends/distributions, net income attributable to noncontrolling interests, interest expense, losses from early extinguishment of debt, unrealized loss on non-real estate investment, net operating income from unconsolidated joint ventures, loss from unconsolidated joint ventures, depreciation and amortization expense, transaction costs, payroll and related costs from management services contracts and corporate general and administrative expense less (2) gains (losses) from investments in securities, other income - assignment fee, interest and other income (loss), gains on sales-type lease, gains on sales of real estate, direct reimbursements of payroll and related costs from management services contracts and development and management services revenue. The Company believes NOI is useful to investors as a performance measure and believes it provides useful information to investors regarding its results of operations and financial condition because, when compared across periods, it reflects the impact on operations from trends in occupancy rates, rental rates, operating costs and acquisition and development activity on an unleveraged basis, providing perspective not immediately apparent from net income attributable to Boston Properties, Inc. common shareholders and net income attributable to Boston Properties Limited Partnership common unitholders. For example, interest expense is not necessarily linked to the operating performance of a real estate asset and is often incurred at the corporate level as opposed to the property level. Similarly, interest expense may be incurred at the property level even though the

financing proceeds may be used at the corporate level (e.g., used for other investment activity). In addition, depreciation and amortization expense, because of historical cost accounting and useful life estimates, may distort operating performance measures at the property level. NOI presented by the Company may not be comparable to NOI reported by other REITs or real estate companies that define NOI differently.

The Company’s internal reporting utilizes its share of NOI, which includes its share of NOI from consolidated and unconsolidated joint ventures, which is a non-GAAP financial measure that is calculated as the consolidated amount, plus the Company’s share of the amount from the Company’s unconsolidated joint ventures (calculated based upon the Company’s economic percentage ownership interest and, in some cases, after priority allocations), less the Company’s partners’ share of the amount from the Company’s consolidated joint ventures (calculated based upon the partners’ economic percentage ownership interests and, in some cases, after priority allocations, income allocation to private REIT shareholders and their share of fees due to the Company). The Company’s share of NOI from unconsolidated joint ventures does not include its share of losses from early extinguishment of debt from unconsolidated joint ventures, gains on sales of real estate from unconsolidated joint ventures and gain on sale of investment from unconsolidated joint ventures, both of which are included within Income (Loss) From Unconsolidated Joint Ventures in the Company’s Consolidated Statements of Operations. Management utilizes its share of NOI in assessing its performance as the Company has several significant joint ventures and, in some cases, the Company exercises significant influence over, but does not control, the joint venture, in which case GAAP requires that the Company account for the joint venture entity using the equity method of accounting and the Company does not consolidate it for financial reporting purposes. In other cases, GAAP requires that the Company consolidate the venture even though the Company’s partner(s) owns a significant percentage interest. As a result, the presentations of the Company’s share of NOI should not be considered a substitute for, and should only be considered together with and as a supplement to, the Company’s financial information presented in accordance with GAAP.

Asset information by segment is not reported because the Company does not use this measure to assess performance. Therefore, depreciation and amortization expense is not allocated among segments. Preferred stock/unit redemption charge, preferred dividends/distributions, interest expense, losses from early extinguishment of debt, unrealized loss on non-real estate investment, loss from unconsolidated joint ventures, depreciation and amortization expense, transaction costs, payroll and related costs from management services contracts, corporate general and administrative expense, gains (losses) from investments in securities, other income - assignment fee, interest and other income (loss), gain on sales-type lease, gains on sales of real estate, direct reimbursements of payroll and related costs from management services contracts and development and management services revenue are not included in NOI and are provided as reconciling items to the Company’s reconciliations of its share of NOI to net income attributable to common shareholders/unitholders.

The Company’s segments are based on the Company’s method of internal reporting which classifies its operations by geographic area. The Company’s segments by geographic area are Boston, Los Angeles, New York, San Francisco, Seattle and Washington, DC. On September 1, 2021, the Company invested in a joint venture that acquired Safeco Plaza located in Seattle, Washington. As such, the Seattle region was identified as a segment during the third quarter of 2021. The Company also presents information for each segment by property type, including Premier Workplace (which includes office, life sciences and retail), Residential and Hotel.

Parking and other revenue for the year ended December 31, 2022 increased by approximately $25.4 million compared to 2021. These increases were primarily in transient and monthly parking revenue.

Information by geographic area and property type (dollars in thousands):

For the year ended December 31, 2022:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Premier Workplace	$	1,005,156		$	—		$	1,031,479		$	534,397		$	31,978		$	365,402		$	2,968,412
Residential	15,086			—			—			14,769			—			27,326			57,181
Hotel	39,482			—			—			—			—			—			39,482
Total	1,059,724			—			1,031,479			549,166			31,978			392,728			3,065,075
% of Grand Totals	34.58		%	—		%	33.65		%	17.92		%	1.04		%	12.81		%	100.00		%
Rental Expenses:
Premier Workplace	360,218			—			391,293			183,353			8,386			135,237			1,078,487
Residential	5,961			—			—			11,371			—			12,251			29,583
Hotel	27,478			—			—			—			—			—			27,478
Total	393,657			—			391,293			194,724			8,386			147,488			1,135,548
% of Grand Totals	34.66		%	—		%	34.46		%	17.15		%	0.74		%	12.99		%	100.00		%
Net operating income	$	666,067		$	—		$	640,186		$	354,442		$	23,592		$	245,240		$	1,929,527
% of Grand Totals	34.52		%	—		%	33.18		%	18.37		%	1.22		%	12.71		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(45,822)			—			(145,990)			—			—			—			(191,812)
Add: Company’s share of net operating income (loss) from unconsolidated joint ventures	34,233			53,023			1,594			12,785			7,690			36,756			146,081
Company’s share of net operating income	$	654,478		$	53,023		$	495,790		$	367,227		$	31,282		$	281,996		$	1,883,796
% of Grand Totals	34.75		%	2.81		%	26.32		%	19.49		%	1.66		%	14.97		%	100.00		%

_______________

For the year ended December 31, 2021:


	Boston			Los Angeles			New York			San Francisco			Seattle				Washington, DC			Total
Rental Revenue: (1)
Premier Workplace	$	930,560		$	—		$	1,012,172		$	508,620		$	—			$	340,808		$	2,792,160
Residential	13,397			—			—			3,892			—				25,379			42,668
Hotel	13,609			—			—			—			—				—			13,609
Total	957,566			—			1,012,172			512,512			—				366,187			2,848,437
% of Grand Totals	33.62		%	—		%	35.53		%	17.99		%	—		%		12.86		%	100.00		%
Rental Expenses:
Premier Workplace	322,298			—			379,267			168,040			—				127,102			996,707
Residential	5,811			—			—			6,717			—				11,916			24,444
Hotel	12,998			—			—			—			—				—			12,998
Total	341,107			—			379,267			174,757			—			—	139,018			1,034,149
% of Grand Totals	32.98		%	—		%	36.67		%	16.90		%	—		%		13.45		%	100.00		%
Net operating income	$	616,459		$	—		$	632,905		$	337,755		$	—			$	227,169		$	1,814,288
% of Grand Totals	33.98		%	—		%	34.88		%	18.62		%	—		%		12.52		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(43,232)			—			(143,072)			—			—				—			(186,304)
Add: Company’s share of net operating income (loss) from unconsolidated joint ventures	16,551			51,641			(664)			14,152			2,498				23,578			107,756
Company’s share of net operating income	$	589,778		$	51,641		$	489,169		$	351,907		$	2,498			$	250,747		$	1,735,740
% of Grand Totals	33.98		%	2.98		%	28.18		%	20.27		%	0.14		%		14.45		%	100.00		%

_______________

For the year ended December 31, 2020:


	Boston			Los Angeles			New York			San Francisco			Washington, DC			Total
Rental Revenue: (1)
Premier Workplace	$	897,915		$	—		$	935,966		$	508,327		$	336,587		$	2,678,795
Residential	13,616			—			—			155			24,375			38,146
Hotel	7,478			—			—			—			—			7,478
Total	919,009			—			935,966			508,482			360,962			2,724,419
% of Grand Totals	33.73		%	—		%	34.36		%	18.66		%	13.25		%	100.00		%
Rental Expenses:
Premier Workplace	318,509			—			384,753			163,156			132,051			998,469
Residential	5,378			—			—			2,261			11,100			18,739
Hotel	13,136			—			—			—			—			13,136
Total	337,023			—			384,753			165,417			143,151			1,030,344
% of Grand Totals	32.71		%	—		%	37.35		%	16.05		%	13.89		%	100.00		%
Net operating income	$	581,986		$	—		$	551,213		$	343,065		$	217,811		$	1,694,075
% of Grand Totals	34.35		%	—		%	32.54		%	20.25		%	12.86		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(41,849)			—			(121,038)			—			—			(162,887)
Add: Company’s share of net operating income from unconsolidated joint ventures	10,765			57,907			(5,326)			14,928			16,669			94,943
Company’s share of net operating income	$	550,902		$	57,907		$	424,849		$	357,993		$	234,480		$	1,626,131
% of Grand Totals	33.88		%	3.56		%	26.12		%	22.02		%	14.42		%	100.00		%

_______________

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8924-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 34
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8981-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
-Paragraph 21
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8721-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 32
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (e)
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 280
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8657-108599

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8721-108599

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-URI https://asc.fasb.org/topic&trid=2134510

+ Details

Schedule of Finite Lived Intagible Assets Future Amortization Expense (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
2023	$ 27,659
2024	21,595
2025	21,419
2026	20,571
2027	18,214
Above Market Lease Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2023	1,306
2024	401
2025	389
2026	389
2027	389
Below Market Lease [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2023	13,439
2024	9,811
2025	9,768
2026	8,647
2027	$ 5,477

Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($)

3 Months Ended

12 Months Ended

Dec. 19, 2022

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Net income attributable to the company's common shareholders / unitholders

$ 111,882,000

$ 184,537,000

$ 848,947,000

$ 496,223,000

$ 862,227,000

Preferred Stock Redemption Charge

(6,412,000)

Preferred dividends / distributions

(2,560,000)

(10,500,000)

Noncontrolling interest-common units of the Operating Partnership

(96,780,000)

(55,931,000)

(97,704,000)

Noncontrolling interest in property partnerships

(74,857,000)

(70,806,000)

(48,260,000)

Interest expense

(437,139,000)

(423,346,000)

(431,717,000)

Losses from early extinguishment of debt

45,182,000

Unrealized Gain (Loss) on Investments

150,000

Company's share of net operating income from joint ventures

(1,929,527,000)

(1,814,288,000)

(1,694,075,000)

Loss from unconsolidated joint ventures

59,840,000

2,570,000

85,110,000

Depreciation and amortization expense

(749,775,000)

(717,336,000)

(683,751,000)

Transaction costs

(2,905,000)

(5,036,000)

(1,531,000)

General and administrative expense

(146,378,000)

(151,573,000)

(133,112,000)

Gains (losses) from investments in securities

6,453,000

(5,626,000)

(5,261,000)

Other Income - assignment fee

(6,624,000)

Interest and other income (loss)

(11,940,000)

(5,704,000)

(5,953,000)

Sales-type and Direct Financing Leases, Profit (Loss)

$ (10,100,000)

(10,058,000)

Gains on sales of real estate

(437,019,000)

(123,660,000)

(618,982,000)

Segment Reconciling Items

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Net income attributable to the company's common shareholders / unitholders

848,947,000

496,223,000

862,227,000

Preferred Stock Redemption Charge

6,412,000

Preferred dividends / distributions

2,560,000

10,500,000

Noncontrolling interest-common units of the Operating Partnership

96,780,000

55,931,000

97,704,000

Noncontrolling interest in property partnerships

74,857,000

70,806,000

48,260,000

Interest expense

437,139,000

423,346,000

431,717,000

Losses from early extinguishment of debt

45,182,000

Unrealized Gain (Loss) on Investments

150,000

Loss from unconsolidated joint ventures

59,840,000

2,570,000

85,110,000

Depreciation and amortization expense

749,775,000

717,336,000

683,751,000

Transaction costs

2,905,000

5,036,000

1,531,000

Operating expense

15,450,000

12,487,000

11,626,000

General and administrative expense

146,378,000

151,573,000

133,112,000

Gains (losses) from investments in securities

(6,453,000)

5,626,000

5,261,000

Other Income - assignment fee

6,624,000

Interest and other income (loss)

11,940,000

5,704,000

5,953,000

Sales-type and Direct Financing Leases, Profit (Loss)

(10,058,000)

Gains on sales of real estate

437,019,000

123,660,000

618,982,000

Other revenue

15,450,000

12,487,000

11,626,000

Company's share of Net Operating Income

1,883,796,000

1,735,740,000

1,626,131,000

Unconsolidated Joint Ventures [Member]

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Interest expense

(154,065,000)

(108,884,000)

(98,051,000)

Losses from early extinguishment of debt

1,327,000

Company's share of net operating income from joint ventures

(146,081,000)

(107,756,000)

(94,943,000)

Loss from unconsolidated joint ventures

59,840,000

2,570,000

85,110,000

Depreciation and amortization expense

(181,041,000)

(147,121,000)

(141,853,000)

Transaction costs

(837,000)

(470,000)

(1,027,000)

Gains on sales of real estate

(11,737,000)

^[1]

Unconsolidated Joint Ventures [Member] | Segment Reconciling Items

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Company's share of net operating income from joint ventures

94,943,000

Boston Properties Limited Partnership

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Net income attributable to the company's common shareholders / unitholders

957,265,000

561,993,000

979,979,000

Preferred Stock Redemption Charge

(6,412,000)

Preferred dividends / distributions

(2,560,000)

(10,500,000)

Noncontrolling interest in property partnerships

(74,857,000)

(70,806,000)

(48,260,000)

Interest expense

(437,139,000)

(423,346,000)

(431,717,000)

Losses from early extinguishment of debt

45,182,000

Unrealized Gain (Loss) on Investments

150,000

Loss from unconsolidated joint ventures

59,840,000

2,570,000

85,110,000

Depreciation and amortization expense

(742,293,000)

(709,035,000)

Transaction costs

(2,905,000)

(5,036,000)

(1,531,000)

General and administrative expense

(146,378,000)

(151,573,000)

(133,112,000)

Gains (losses) from investments in securities

6,453,000

(5,626,000)

(5,261,000)

Other Income - assignment fee

(6,624,000)

Interest and other income (loss)

(11,940,000)

(5,704,000)

(5,953,000)

Sales-type and Direct Financing Leases, Profit (Loss)

(10,058,000)

Gains on sales of real estate

(441,075,000)

(125,198,000)

(631,945,000)

Boston Properties Limited Partnership | Segment Reconciling Items

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Net income attributable to the company's common shareholders / unitholders

957,265,000

561,993,000

979,979,000

Preferred Stock Redemption Charge

6,412,000

Preferred dividends / distributions

2,560,000

10,500,000

Noncontrolling interest in property partnerships

74,857,000

70,806,000

48,260,000

Interest expense

437,139,000

423,346,000

431,717,000

Losses from early extinguishment of debt

45,182,000

Unrealized Gain (Loss) on Investments

150,000

Loss from unconsolidated joint ventures

59,840,000

2,570,000

85,110,000

Depreciation and amortization expense

742,293,000

709,035,000

676,666,000

Transaction costs

2,905,000

5,036,000

1,531,000

Operating expense

15,450,000

12,487,000

11,626,000

General and administrative expense

146,378,000

151,573,000

133,112,000

Gains (losses) from investments in securities

(6,453,000)

5,626,000

5,261,000

Other Income - assignment fee

6,624,000

Interest and other income (loss)

11,940,000

5,704,000

5,953,000

Sales-type and Direct Financing Leases, Profit (Loss)

(10,058,000)

Gains on sales of real estate

441,075,000

125,198,000

631,945,000

Other revenue

15,450,000

12,487,000

11,626,000

Company's share of Net Operating Income

1,883,796,000

1,735,740,000

1,626,131,000

Management Service [Member]

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Other revenue

(28,056,000)

(27,697,000)

(29,641,000)

Management Service [Member] | Segment Reconciling Items

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Other revenue

28,056,000

27,697,000

29,641,000

Management Service [Member] | Boston Properties Limited Partnership

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Other revenue

(28,056,000)

(27,697,000)

(29,641,000)

Management Service [Member] | Boston Properties Limited Partnership | Segment Reconciling Items

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Other revenue

28,056,000

27,697,000

29,641,000

Noncontrolling interest - property partnerships [Member]

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Company's share of net operating income from joint ventures

191,812,000

186,304,000

162,887,000

Noncontrolling interest - property partnerships [Member] | Segment Reconciling Items

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Company's share of net operating income from joint ventures

191,812,000

186,304,000

162,887,000

Noncontrolling interest - property partnerships [Member] | Boston Properties Limited Partnership | Segment Reconciling Items

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Company's share of net operating income from joint ventures

$ 191,812,000

$ 186,304,000

$ 162,887,000

[1]	For the year ended December 31, 2020, represents the gain on sale of Annapolis Junction Building Eight and two land parcels. The gain on sale of real estate is included in Loss from Unconsolidated Joint Ventures in the Company’s Consolidated Statements of Operations.

Comprehensive Text Block List (Policies)	12 Months Ended
Comprehensive Text Block List (Policies)	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements are presented using the accrual basis of accounting in conformity with accounting principles generally accepted in the United States of America. BXP does not have any other significant assets, liabilities or operations, other than its investment in BPLP, nor does it have employees of its own. BPLP, not BXP, generally executes all significant business relationships other than transactions involving securities of BXP. All majority-owned subsidiaries and joint ventures over which the Company has financial and operating control and variable interest entities (“VIEs”) in which the Company has determined it is the primary beneficiary are included in the consolidated financial statements. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for all other unconsolidated joint ventures using the equity method of accounting. Accordingly, the Company’s share of the earnings of these joint ventures and companies is included in consolidated net income.
Consolidation, Variable Interest Entity, Policy	Variable Interest Entities (VIEs)Consolidated VIEs are those for which the Company is considered to be the primary beneficiary of a VIE. The primary beneficiary is the entity that has a controlling financial interest in the VIE, which is defined by the entity having both of the following characteristics: (1) the power to direct the activities that, when taken together, most significantly impact the VIE’s performance and (2) the obligation to absorb losses or the right to receive the returns from the VIE that could potentially be significant to the VIE. The assets of each VIE are only available to satisfy such VIE's respective liabilities.

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,789,029 and $6,702,830 at December 31, 2022 and December 31, 2021, respectively)	$ 25,389,663	$ 23,752,630
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at December 31, 2022 and December 31, 2021, respectively)	237,510	237,507
Less: accumulated depreciation (amounts related to VIEs of $(1,381,401) and $(1,283,060) at December 31, 2022 and December 31, 2021, respectively)	(6,298,082)	(5,883,961)
Cash and cash equivalents (amounts related to VIEs of $259,658 and $300,937 at December 31, 2022 and December 31, 2021, respectively)	690,333	452,692
Tenant and other receivables, net (amounts related to VIEs of $16,521 and $6,824 at December 31, 2022 and December 31, 2021, respectively)	81,389	70,186
Accrued rental income, net (amounts related to VIEs of $367,138 and $357,395 at December 31, 2022 and December 31, 2021, respectively)	1,276,580	1,226,745
Deferred charges, net (amounts related to VIEs of $176,597 and $174,637 at December 31, 2022 and December 31, 2021, respectively)	733,282	618,798
Prepaid expenses and other assets (amounts related to VIEs of $11,647 and $29,668 at December 31, 2022 and December 31, 2021, respectively)	43,589	57,811
Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)	3,272,368	3,267,914
Lease liabilities - finance leases (amounts related to VIEs of $20,604 and $20,458 at December 31, 2022 and December 31, 2021, respectively)	249,335	244,421
Accounts payable and accrued expenses (amounts related to VIEs of $29,466 and $29,464 at December 31, 2022 and December 31, 2021, respectively)	417,545	320,775
Other liabilities (amounts related to VIEs of $114,232 and $150,131 at December 31, 2022 and December 31, 2021, respectively)	$ 450,918	$ 391,441
Reedemable deferred stock units, units	97,853	83,073
Limited Partners' Capital Account, Units Outstanding (in units)	155,008,185
General Partners' Capital Account, Units Outstanding (in units)	1,749,682
Excess stock, par value	$ 0.01	$ 0.01
Excess stock, shares authorized	150,000,000	150,000,000
Excess stock, shares outstanding	0	0
Excess stock, shares issued	0	0
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock / units, shares / units issued (in shares / units)	0	0
Preferred stock / units, shares / units outstanding (in shares / units)	0	0
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	156,836,767	156,623,749
Common Stock, Shares, Outstanding	156,757,867	156,544,849
Treasury common stock at cost, shares	78,900	78,900
Boston Properties Limited Partnership
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,789,029 and $6,702,830 at December 31, 2022 and December 31, 2021, respectively)	$ 25,022,149	$ 23,379,243
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at December 31, 2022 and December 31, 2021, respectively)	237,510	237,507
Less: accumulated depreciation (amounts related to VIEs of $(1,381,401) and $(1,283,060) at December 31, 2022 and December 31, 2021, respectively)	(6,180,474)	(5,772,018)
Cash and cash equivalents (amounts related to VIEs of $259,658 and $300,937 at December 31, 2022 and December 31, 2021, respectively)	690,333	452,692
Tenant and other receivables, net (amounts related to VIEs of $16,521 and $6,824 at December 31, 2022 and December 31, 2021, respectively)	81,389	70,186
Accrued rental income, net (amounts related to VIEs of $367,138 and $357,395 at December 31, 2022 and December 31, 2021, respectively)	1,276,580	1,226,745
Deferred charges, net (amounts related to VIEs of $176,597 and $174,637 at December 31, 2022 and December 31, 2021, respectively)	733,282	618,798
Prepaid expenses and other assets (amounts related to VIEs of $11,647 and $29,668 at December 31, 2022 and December 31, 2021, respectively)	43,589	57,811
Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)	3,272,368	3,267,914
Lease liabilities - finance leases (amounts related to VIEs of $20,604 and $20,458 at December 31, 2022 and December 31, 2021, respectively)	249,335	244,421
Accounts payable and accrued expenses (amounts related to VIEs of $29,466 and $29,464 at December 31, 2022 and December 31, 2021, respectively)	417,545	320,775
Other liabilities (amounts related to VIEs of $114,232 and $150,131 at December 31, 2022 and December 31, 2021, respectively)	$ 450,918	$ 391,441
Reedemable deferred stock units, units	97,853	83,073
Limited Partners' Capital Account, Units Outstanding (in units)	155,008,185	154,798,935
General Partners' Capital Account, Units Outstanding (in units)	1,749,682	1,745,914
NonControlling Interest Redeemable Partnership Units Common Units Shares Outstanding	16,531,172	16,561,186
NonControlling Interest Redeemable Partnership Units Common Units Long Term Incentive Units At Redemption Value Shares Outstanding	1,679,175	1,485,376
Variable Interest Entity, Primary Beneficiary [Member]
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,789,029 and $6,702,830 at December 31, 2022 and December 31, 2021, respectively)	$ 6,789,029	$ 6,702,830
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at December 31, 2022 and December 31, 2021, respectively)	21,000	21,000
Less: accumulated depreciation (amounts related to VIEs of $(1,381,401) and $(1,283,060) at December 31, 2022 and December 31, 2021, respectively)	(1,381,401)	(1,283,060)
Cash and cash equivalents (amounts related to VIEs of $259,658 and $300,937 at December 31, 2022 and December 31, 2021, respectively)	259,658	300,937
Tenant and other receivables, net (amounts related to VIEs of $16,521 and $6,824 at December 31, 2022 and December 31, 2021, respectively)	16,521	6,824
Accrued rental income, net (amounts related to VIEs of $367,138 and $357,395 at December 31, 2022 and December 31, 2021, respectively)	367,138	357,395
Deferred charges, net (amounts related to VIEs of $176,597 and $174,637 at December 31, 2022 and December 31, 2021, respectively)	176,597	174,637
Prepaid expenses and other assets (amounts related to VIEs of $11,647 and $29,668 at December 31, 2022 and December 31, 2021, respectively)	11,647	29,668
Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)	3,272,368	3,267,914
Lease liabilities - finance leases (amounts related to VIEs of $20,604 and $20,458 at December 31, 2022 and December 31, 2021, respectively)	20,604	20,458
Accounts payable and accrued expenses (amounts related to VIEs of $29,466 and $29,464 at December 31, 2022 and December 31, 2021, respectively)	29,466	29,464
Other liabilities (amounts related to VIEs of $114,232 and $150,131 at December 31, 2022 and December 31, 2021, respectively)	114,232	150,131
Variable Interest Entity, Primary Beneficiary [Member] \| Boston Properties Limited Partnership
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,789,029 and $6,702,830 at December 31, 2022 and December 31, 2021, respectively)	6,789,029	6,702,830
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at December 31, 2022 and December 31, 2021, respectively)	21,000	21,000
Less: accumulated depreciation (amounts related to VIEs of $(1,381,401) and $(1,283,060) at December 31, 2022 and December 31, 2021, respectively)	(1,381,401)	(1,283,060)
Cash and cash equivalents (amounts related to VIEs of $259,658 and $300,937 at December 31, 2022 and December 31, 2021, respectively)	259,658	300,937
Tenant and other receivables, net (amounts related to VIEs of $16,521 and $6,824 at December 31, 2022 and December 31, 2021, respectively)	16,521	6,824
Accrued rental income, net (amounts related to VIEs of $367,138 and $357,395 at December 31, 2022 and December 31, 2021, respectively)	367,138	357,395
Deferred charges, net (amounts related to VIEs of $176,597 and $174,637 at December 31, 2022 and December 31, 2021, respectively)	176,597	174,637
Prepaid expenses and other assets (amounts related to VIEs of $11,647 and $29,668 at December 31, 2022 and December 31, 2021, respectively)	11,647	29,668
Mortgage notes payable, net (amounts related to VIEs of $3,272,368 and $3,267,914 at December 31, 2022 and December 31, 2021, respectively)	3,272,368	3,267,914
Lease liabilities - finance leases (amounts related to VIEs of $20,604 and $20,458 at December 31, 2022 and December 31, 2021, respectively)	20,604	20,458
Accounts payable and accrued expenses (amounts related to VIEs of $29,466 and $29,464 at December 31, 2022 and December 31, 2021, respectively)	29,466	29,464
Other liabilities (amounts related to VIEs of $114,232 and $150,131 at December 31, 2022 and December 31, 2021, respectively)	$ 114,232	$ 150,131

Schedule of Unsecured Senior Notes (Details) - USD ($)
$ in Thousands

Dec. 31, 2022

Nov. 17, 2022

Dec. 31, 2021

Debt Instrument [Line Items]

Senior Notes

$ 10,237,968

$ 9,483,695

Boston Properties Limited Partnership

Debt Instrument [Line Items]

Debt Issuance Costs, Net

27,632

Senior Notes

10,237,968

$ 9,483,695

Boston Properties Limited Partnership | Senior Notes

Debt Instrument [Line Items]

Debt

10,300,000

Debt Instrument, Unamortized Discount

14,094

Debt Issuance Costs, Net

47,938

Senior Notes

$ 10,237,968

Boston Properties Limited Partnership | Senior Notes | 3.279% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.125%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.279%

Debt

$ 500,000

Long-term Debt, Maturity Date

^[2]

Sep. 01, 2023

Boston Properties Limited Partnership | Senior Notes | 3.916% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.80%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.916%

Debt

$ 700,000

Long-term Debt, Maturity Date

^[2]

Feb. 01, 2024

Boston Properties Limited Partnership | Senior Notes | 3.350% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.20%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.35%

Debt

$ 850,000

Long-term Debt, Maturity Date

^[2]

Jan. 15, 2025

Boston Properties Limited Partnership | Senior Notes | 3.766% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.65%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.766%

Debt

$ 1,000,000

Long-term Debt, Maturity Date

^[2]

Feb. 01, 2026

Boston Properties Limited Partnership | Senior Notes | 3.495% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.75%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.495%

Debt

$ 1,000,000

Long-term Debt, Maturity Date

^[2]

Oct. 01, 2026

Boston Properties Limited Partnership | Senior Notes | 6.924% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

6.75%

Debt Instrument, Interest Rate, Effective Percentage

6.924%

^[1]

6.924%

Debt

$ 750,000

Long-term Debt, Maturity Date

^[2]

Dec. 01, 2027

Boston Properties Limited Partnership | Senior Notes | 4.628% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

4.50%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

4.628%

Debt

$ 1,000,000

Long-term Debt, Maturity Date

^[2]

Dec. 01, 2028

Boston Properties Limited Partnership | Senior Notes | 3.505% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.40%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.505%

Debt

$ 850,000

Long-term Debt, Maturity Date

^[2]

Jun. 21, 2029

Boston Properties Limited Partnership | Senior Notes | 2.984% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.90%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

2.984%

Debt

$ 700,000

Long-term Debt, Maturity Date

^[2]

Mar. 15, 2030

Boston Properties Limited Partnership | Senior Notes | 3.343 % unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.25%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.343%

Debt

$ 1,250,000

Long-term Debt, Maturity Date

^[2]

Jan. 30, 2031

Boston Properties Limited Partnership | Senior Notes | 2.671% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.55%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

2.671%

Debt

$ 850,000

Long-term Debt, Maturity Date

^[2]

Apr. 01, 2032

Boston Properties Limited Partnership | Senior Notes | 2.524% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.45%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

2.524%

Debt

$ 850,000

Long-term Debt, Maturity Date

^[2]

Oct. 01, 2033

[1]	Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.
[2]	No principal amounts are due prior to maturity.

Leases Narrative (Details) $ in Thousands	12 Months Ended
Leases Narrative (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Lessor, Lease, Description [Line Items]
Write-off (reinstatement) for accrued rent and accounts receivables	$ (1,500)	$ 1,300	$ 90,300
Number of Properties Subject to Ground Leases		4
Property Subject to Operating Lease
Lessor, Lease, Description [Line Items]
Number of Properties Subject to Ground Leases	4	4	4

Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Summary Of Significant Accounting Policies [Line Items]
Interest capitalized	$ 52,130,000	$ 53,097,000	$ 53,881,000
Salaries And Related Costs Capitalized	16,100,000	13,700,000	12,900,000
Cash FDIC Insured Limit	250,000
Separate Unrestricted Cash For Deferred Compensation Plan.	32,300,000	43,600,000
Gains (losses) from investments in securities	$ (6,453,000)	5,626,000	5,261,000
Accounts Receivable, Collection Period Expected	1
Straight Line Rent Adjustments	$ 108,000,000	104,300,000	104,900,000
Above and below market rent adjustments, net	$ 9,100,000	4,200,000	6,500,000
REIT Distribution Requirement	90.00%
Company's Taxable Income Distribution	100.00%
Unrealized Gain (Loss) on Investments	$ (150,000)	$ 0	$ 0
Environmental Focused Investment Fund
Summary Of Significant Accounting Policies [Line Items]
Unrealized Gain (Loss) on Investments	$ (200,000)

Lease Liability Maturity Schedule (Details) - USD ($)
$ in Thousands

Dec. 31, 2022

Dec. 31, 2021

Lessee, Operating Lease, Liability, Payment, Due [Abstract]

2023

$ 22,415

$ 19,623

2024

22,274

25,333

2025

10,308

10,085

2026

10,100

10,307

2027

9,885

10,100

Thereafter

528,915

538,801

Total lease payments

603,897

614,249

Less: Interest Portion

399,211

409,688

Present value of lease payments

204,686

204,561

Finance Lease, Liability, Payment, Due [Abstract]

2023

9,306

8,762

2024

49,343

^[1]

10,826

2025

9,971

48,605

^[1]

2026

10,166

9,971

2027

10,364

10,166

Thereafter

1,352,647

1,363,011

Total lease payments

1,441,797

1,451,341

Less: Interest Portion

1,192,462

1,206,920

Lease liabilities - finance leases

249,335

244,421

Lessee, Lease, Description [Line Items]

Lessee purchase option reasonably certain of exercising

$ 38,700

[1]	Finance lease payments in 2024 include approximately $38.7 million related to a purchase option that the Company is reasonably certain it will exercise.