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Net of the adjustment for the equity component allocation

$ 93,628

Mortgage notes payable, net

3,047,586

$ 2,643,301

Unsecured senior notes

3,016,598

2,172,389

Unsecured exchangeable senior notes

1,721,817

1,904,081

ASC Four Seven Zero Dash Two Zero Adjustment [Member]

Net of the adjustment for the equity component allocation

93,600

140,400

Carrying Amount [Member]

Mortgage notes payable, net

3,047,586

2,643,301

Unsecured senior notes

3,016,598

2,172,389

Unsecured exchangeable senior notes

^[1]

1,721,817

1,904,081

Total

7,786,001

6,719,771

Estimated Fair Value [Member]

Mortgage notes payable, net

3,121,193

2,615,099

Unsecured senior notes

3,241,542

2,318,868

Unsecured exchangeable senior notes

1,929,291

2,059,796

Total

$ 8,292,026

$ 6,993,763

[1]	Includes the net impact of ASC 470-20 (formerly known as FSP No. APB 14-1) totaling approximately $93.6 million and $140.4 million at December 31, 2010 and 2009, respectively (See Note 8).

Summary of Significant Accounting Policies (GAAP Reconciliation of Net Income to Taxable Income) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2009	Jun. 30, 2009	Mar. 31, 2009	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Statement [Line Items]
Net income attributable to Boston Properties Limited Partnership	$ (12,402)	$ 68,436	$ 72,842	$ 62,867	$ 63,479	$ 77,819	$ 80,466	$ 54,586	$ 191,743	$ 276,350	$ 132,525
GAAP Reconciliation of Net Income to Taxable Income [Member]
Statement [Line Items]
Net income attributable to Boston Properties Limited Partnership									191,743	276,350	132,525
Straight line rent adjustments									(87,503)	(44,529)	(24,025)
Book/Tax differences from depreciation and amortization									70,276	56,276	87,565
Book/Tax differences on gains/losses from capital transactions									(2,734)	(11,760)	(33,340)
Book/Tax differences from stock-based compensation									(2,255)	18,568	(22,695)
Book/Tax differences on losses from early extinguishments of debt									7,429
Impairment loss on investments in unconsolidated joint ventures										7,413	188,325
Other book/tax differences, net									12,450	13,503	39,158
Taxable income									$ 189,406	$ 315,821	$ 367,513

Real Estate (Schedule of Real Estate) (Details) - USD ($) $ in Thousands	Dec. 31, 2010	Dec. 31, 2009
Real Estate
Land	$ 2,107,708	$ 1,874,004
Land held for future development	753,651	714,620
Buildings and improvements	7,275,523	6,561,240
Tenant improvements	1,090,462	922,224
Furniture, fixtures and equipment	24,043	23,679
Construction in progress	1,073,402	563,645
Total	12,324,789	10,659,412
Less: accumulated depreciation	(2,282,835)	(2,000,917)
Total real estate	$ 10,041,954	$ 8,658,495

Real Estate (Narrative) (Details) $ in Thousands	12 Months Ended				24 Months Ended	36 Months Ended
Real Estate (Narrative) (Details) $ in Thousands	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($) sqft	Dec. 31, 2009 USD ($)	Dec. 31, 2008 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($) sqft	Dec. 29, 2010 USD ($)
Statement [Line Items]
Acquisition closing costs		$ 2,614
Mortgage note payable assumed in connection with the acquisition of real estate		843,104
Mortgage outstanding		3,047,586	$ 2,643,301			$ 3,047,586
Cash Deposit		10,000
Gain on sale recognized		2,734	11,760	$ 33,340
Five One Zero Madison Avenue [Member]
Statement [Line Items]
Acquisition aggregate purchase price		287,000				$ 287,000
Acquisition closing costs		$ 1,500
Acquisition date		September 24, 2010
Junior mezzanine loan interest acquisition cost		$ 22,500
Net Rentable Square Feet Of Acquisition \| sqft		347,000				347,000
Mortgage note payable assumed in connection with the acquisition of real estate		$ 202,600
Mortgage outstanding		$ 267,500				$ 267,500
Variable interest spread over LIBOR		0.30%
Maturity date		Feb. 24, 2012
Bay Colony Corporate Center [Member]
Statement [Line Items]
Acquisition aggregate purchase price	$ 185,000				$ 185,000
Acquisition date	February 1, 2011
Portion of acquisition included in debt	$ 143,900				143,900
Cash portion of purchase price	$ 41,100				$ 41,100
Maturity date	Jun. 11, 2012	Jun. 11, 2012
Interest at a fixed rate	6.53%				6.53%
John Hancock Tower and Garage in Boston [Member]
Statement [Line Items]
Acquisition aggregate purchase price		$ 930,000				930,000	$ 930,000
Acquisition closing costs		$ 900
Acquisition date		December 29, 2010
Portion of acquisition included in debt		$ 640,500				$ 640,500	$ 640,500
Net Rentable Square Feet Of Acquisition \| sqft		1,700,000				1,700,000
Cash portion of purchase price		$ 289,500				$ 289,500
Maturity date		Jan. 06, 2017
Interest at a fixed rate		5.68%				5.68%
Estimated cost of projects and improvements		$ 46,000
Estimated cost of projects and improvements, aggregate cost to complete		$ 35,300
Number of levels in parking facility		8
Number of stories in building		62
Number of spaces in parking facility		2,013
Two Five Zero West Fifty-Fifth Street [Member]
Statement [Line Items]
Office building, construction suspended, square feet \| sqft		1,000,000				1,000,000
Costs accrued related to suspension of development			27,800
Settlement of termination of the lease agreement		$ 12,800				$ 12,800
Amount recognized due to termination of the lease agreement		$ 7,200
Weston Corporate Center In Weston Massachusetts [Member]
Statement [Line Items]
Net rentable area (square feet)		356,000
Office property percentage leased		100.00%
Atlantic Wharf Development in Boston [Member]
Statement [Line Items]
Office property percentage leased	79.00%
Residential rental apartments, units		86
Wharf project retail space, square feet		10,000
Partners contribution to the project		$ 14,000
Number of installments					3
Installment years	2011	2010
Greater Washington, DC [Member]
Statement [Line Items]
Deferred gain on sale of parcel sold		$ 33,700
Net rentable square feet of development \| sqft		165,000
Gain on sale recognized		$ 1,800				23,400
Two Eight Zero Park Avenue [Member]
Statement [Line Items]
Gain on sale recognized		1,000
Management fees revenue		12,200
Reston Virginia [Member]
Statement [Line Items]
Acquisition aggregate purchase price		$ 20,300				$ 20,300
Acquisition date		July 1, 2010
Contractual Amount Of Lease Agreement [Member] \| Two Five Zero West Fifty-Fifth Street [Member]
Statement [Line Items]
Costs accrued related to suspension of development			$ 20,000

Real Estate (Schedule of Allocation of the Aggregate Purchase Price of Acquisition) (Details) - John Hancock Tower and Garage in Boston [Member] - USD ($) $ in Thousands	Dec. 31, 2010	Dec. 29, 2010
Statement [Line Items]
Land		$ 219,543
Buildings and improvements		627,074
Tenant improvements		40,810
Tenant leasing costs		114,494
Other assets/liabilities, net		33,045
Above market rents		15,368
Below market rents, net		(97,481)
Above market assumed debt adjustment		(22,853)
Aggregate purchase price	$ 930,000	930,000
Less: Indebtedness assumed	$ (640,500)	(640,500)
Net assets acquired		$ 289,500

Real Estate (Estimated Annual Amortization of the Acquired Below Market Leases (Net of Acquired Above Market Leases) and the Acquired In-Place Lease Intangibles) (Details) - John Hancock Tower and Garage in Boston [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2010 USD ($)
Acquired In-Place Lease Intangible [Member]
Statement [Line Items]
2011	$ 20,659
2012	19,305
2013	17,792
2014	15,890
2015	5,607
Acquired Net Below Market Lease Intangible [Member]
Statement [Line Items]
2011	(9,313)
2012	(9,389)
2013	(9,332)
2014	(9,171)
2015	$ (5,124)

Real Estate (Unaudited Pro Forma In Connection With Acquisition) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2009
Statement [Line Items]
Total revenue	$ 1,657,995	$ 1,625,309
Income from continuing operations	177,627	251,635
Net income attributable to Boston Properties, Inc.	$ 173,554	$ 257,023
Net income per share attributable to Boston Properties, Inc.	$ 1.09	$ 1.70
Net income per share attributable to Boston Properties, Inc.	$ 1.08	$ 1.69

Deferred Charges (Details) - USD ($) $ in Thousands	Dec. 31, 2010	Dec. 31, 2009
Deferred Charges
Leasing costs (and lease related intangibles)	$ 558,620	$ 399,302
Financing costs	89,680	76,915
Deferred costs, gross	648,300	476,217
Less: Accumulated amortization	(212,281)	(181,822)
Deferred charges, total	$ 436,019	$ 294,395

Investments in Unconsolidated Joint Ventures (Investments in Unconsolidated Joint Ventures Table) (Details)

Dec. 31, 2010

Square Four Zero Seven Limited Partnership [Member]

50.00%

The Metropolitan Square Associates LLC [Member]

Market Square North

51.00%

BP/CRF Nine Zero One New York Avenue LLC [Member]

Metropolitan Square

25.00%

^[1]

WP Project Developer LLC [Member]

901 New York Avenue

33.30%

^[2]

RBP Joint Venture LLC [Member]

Wisconsin Place Land and Infrastructure

50.00%

^[3]

Boston Properties Office Value-Added Fund, L.P. [Member]

Eighth Avenue and 46th Street

36.90%

^[1],[4]

Annapolis Junction NFM, LLC [Member]

300 Billerica Road and Mountain View Research and Technology Parks

50.00%

^[5]

Parcels of undeveloped land

Annapolis Junction

0.67

Seven Six Seven Venture, LLC [Member]

60.00%

Two GCT Venture LLC [Member]

The General Motors Building

60.00%

Five Four Zero Madison Venture LLC [Member]

Two Grand Central Tower

60.00%

One Two Five West Fifty-Fifth Street Venture LLC [Member]

540 Madison Avenue

60.00%

Five Zero Zero North Capitol LLC [Member]

125 West 55th Street

30.00%

Three Zero Zero Billerica Road [Member]

500 North Capitol Street, NW

Mountain View Research And Technology Parks [Member]

25.00%

Entity Owning Land And Infrastructure Of Project [Member]

39.50%

33.30%

[1]	The Company's economic ownership can increase based on the achievement of certain return thresholds.
[2]	The Company's wholly-owned entity that owns the office component of the project owns a 33.3% interest in the entity owning the land and infrastructure of the project.
[3]	This property is not in operation and consists of assembled land.
[4]	Represents the Company's effective ownership interest. The Company has a 25.0% interest in the 300 Billerica Road property and a 39.5% interest in the Mountain View Research and Technology Park properties.
[5]	Two of the three Annapolis Junction land parcels are undeveloped land.

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

Dec. 31, 2010

Dec. 31, 2009

Real estate and development in process, net

$ 10,041,954

$ 8,658,495

Outstanding mortgage notes payable

3,047,586

2,643,301

Other liabilities

213,000

127,538

Total liabilities and capital

12,949,100

11,941,317

Carrying value of the Company's investments in unconsolidated joint ventures

767,252

763,636

Unconsolidated Joint Ventures [Member]

Real estate and development in process, net

5,028,851

5,149,868

Other assets

749,308

760,001

Total assets

5,778,159

5,909,869

Outstanding mortgage notes payable

3,151,220

3,217,893

Other liabilities

969,082

1,071,904

Members'/Partners' equity

1,657,857

1,620,072

Total liabilities and capital

5,778,159

5,909,869

Company's share of equity

924,235

927,184

Basis differential

^[1]

(156,983)

(163,548)

Carrying value of the Company's investments in unconsolidated joint ventures

$ 767,252

$ 763,636

[1]

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 occur from impairment of investments 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.

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

3 Months Ended

12 Months Ended

Dec. 31, 2010

Sep. 30, 2010

Jun. 30, 2010

Mar. 31, 2010

Dec. 31, 2009

Sep. 30, 2009

Jun. 30, 2009

Mar. 31, 2009

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Depreciation and amortization

Total revenue

$ 392,482

$ 386,410

$ 393,841

$ 378,071

$ 376,128

$ 375,790

$ 389,048

$ 377,224

$ 1,550,804

$ 1,518,190

$ 1,469,442

330,148

313,458

296,122

Total expenses

932,067

942,436

884,027

Operating income

618,737

575,754

585,415

Interest expense

(378,079)

(322,833)

(295,322)

Gains (losses) from early extinguishments of debt

(89,883)

(510)

Net loss

(198,550)

(282,722)

(138,748)

Income (loss) from unconsolidated joint ventures

36,774

12,058

(182,018)

Unconsolidated Joint Ventures [Member]