Real Estate [Abstract] Real Estate Activity During the Six Months Ended June 30, 2016 Real Estate Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments And Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Peterson Way [Member] Peterson Way [Member] Peterson Way [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Land Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Land Buildings and improvements Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings Tenant Improvements Business Combination RecognizedI dentifiable Assets Acquired And Liabilities Assume Tenant Improvements Amount of tenant improvements acquired at the acquistion date In-place lease intangibles Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Below-market lease intangibles Below Market Lease, Acquired Net assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Subsequent Events [Abstract] Subsequent Events Schedule of Subsequent Events [Table Text Block] Investments In Unconsolidated Joint Ventures [Abstract] Investments In Unconsolidated Joint Ventures [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] BP/CRF 901 New York Avenue LLC [Member] Bp Crf Nine Zero One New York Avenue Llc [Member] BP/CRF Nine Zero One New York Avenue LLC [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Unconsolidated Joint Ventures [Member] Unconsolidated Joint Ventures [Member] Unconsolidated Joint Ventures [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Total revenue Revenues Expenses Costs and Expenses [Abstract] Operating Operating Expenses Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Total expenses Costs and Expenses Operating income Operating Income (Loss) Other expense Other Expenses [Abstract] Interest expense Interest Expense Losses on Extinguishment of Debt Gains (Losses) on Extinguishment of Debt Income (loss) from continuing operations Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Gain on sale or real estate Equity Method Investment, Realized Gain (Loss) on Disposal Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Company's share of net income Companys share of net income (loss) Company's share of net income (loss) Gain on sale of real estate Equity MethodI nvestment Realized Gain Loss On Disposal Company Share Equity MethodI nvestment Realized Gain Loss On Disposal Company Share Basis differential Income Statement Basis Differential Income Statement Basis Differential Elimination of inter-entity interest on partner loan Elimination Of Inter Entity Interest On Partner Loan Elimination Of Inter Entity Interest On Partner Loan Income from unconsolidated joint ventures Income (Loss) from Equity Method Investments Gains on consolidation of joint ventures Gain on Consolidation of Joint Ventures Gain on Consolidation of Joint Ventures Straight-line rent adjustments Straight Line Rent Adjustments "Above" and "below" market rent adjustments, net Above And Below Market Rent Adjustments Above And Below Market Rent Adjustments Distribution related to excess loan proceeds Proceeds from Sale of Equity Method Investments Mortgage notes payable, net Secured Debt Construction Loan Facility Borrowing Capacity Construction Loan Facility Borrowing Capacity Construction Loan Facility Borrowing Capacity Debt Instrument, Basis Spread on Variable Rate Debt Instrument, Basis Spread on Variable Rate Extension Option (in years) Extension Option (in years) Extension Option (in years) Mortgage loan term (in years) Mortgage loan term (in years) Mortgage loan term (in years) Construction Loan Construction Loan Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] VIE Variable Interest Entity, Primary Beneficiary [Member] Boston Properties Limited Partnership Subsidiaries [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series B Cumulative Redeemable Preferred Stock [Member] Series B Cumulative Redeemable Preferred Stock / Unit [Member] Series B Cumulative Redeemable Preferred Stock / Unit [Member] Statement [Line Items] Statement [Line Items] Excess stock, par value Excess Stock Par Or Stated Value Per Share Excess Stock, Par or Stated Value Per Share Excess stock, shares authorized Excess Stock, Shares Authorized Excess stock, shares issued Excess Stock, Shares Issued Excess stock, shares outstanding Excess Stock, Shares Outstanding Preferred stock, par value Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized Series B Dividend Rate Percentage Series B Dividend Rate Percentage Series B Dividend Rate Percentage Series B, Liquidation Preference Per Share (dollars per share) Preferred Stock, Liquidation Preference Per Share Series B, shares issued Preferred Stock, Shares Issued Series B, Shares Outstanding (in shares) Preferred Stock, Shares Outstanding Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Treasury common stock at cost, shares Treasury Stock, Shares NonControlling Interest Redeemable Partnership Units Common Units Shares Outstanding NonControlling Interest Redeemable Partnership Units Common Units Shares Outstanding NonControlling Interest Redeemable Partnership Units Common Units Shares Outstanding NonControlling Interest Redeemable Partnership Units Common Units Long Term Incentive Units At Redemption Value Shares Outstanding NonControlling Interest Redeemable Partnership Units Common Units Long Term Incentive Units At Redemption Value Shares Outstanding NonControlling Interest Redeemable Partnership Units Common Units Long Term Incentive Units At Redemption Value Shares Outstanding General Partners' Capital Account, Units Outstanding General Partners' Capital Account, Units Outstanding Limited Partners' Capital Account, Units Outstanding Limited Partners' Capital Account, Units Outstanding Real Estate Investment Property, at Cost Real Estate Investment Property, at Cost Construction in Progress Construction in Progress, Gross Accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Cash and Cash Equivalents Cash and Cash Equivalents, at Carrying Value Restricted Cash and Cash Equivalents Restricted Cash and Cash Equivalents, Current Accounts Receivable, Net Accounts Receivable, Net Deferred Rent Receivables, Net Deferred Rent Receivables, Net Deferred Charges, net Deferred Costs, Noncurrent Prepaid expense and other assets Prepaid Expense and Other Assets Mezzanine notes payable Subordinated Debt Outside member's notes payable Outside member's notes payable The amount for notes payable (written promise to pay), payable to outside member's, which are due after one year (or one business cycle). Accounts Payable and Accrued Liabilities Accounts Payable and Accrued Liabilities Interest Payable Interest Payable Other Liabilities Other Liabilities Income Statement [Abstract] Revenue Revenues [Abstract] Base rent Operating Leases, Income Statement, Lease Revenue Recoveries from tenants Tenant Reimbursements Parking and other Parking Revenue Total rental revenue Real Estate Revenue, Net Hotel revenue Revenue from Hotels Development and management services Development and management services Development and management services revenue. Total revenue Rental Direct Costs of Leased and Rented Property or Equipment Hotel Direct Costs of Hotels General and administrative General and Administrative Expense Transaction costs Transaction costs expensed Costs expensed to pursue, purchase, lease or otherwise acquire a property, including costs of lease bonuses and options to purchase or lease properties, brokers' fees, recording fees, legal costs, and other costs incurred in acquiring or pursuing properties. Impairment loss Asset Impairment Charges Total expenses Operating income Other income (expense) Other Income and Expenses [Abstract] Income from unconsolidated joint ventures Interest and other income Interest and Other Income Gains (losses) from investments in securities Gain (Loss) on Investments Gains from early extinguishments of debt Interest expense Income before gains on sales of real estate Income (Loss) before Gain or Loss on Sale of Properties, and Extraordinary Items Gains on sales of real estate Gain (Loss) on Sale of Properties, before Applicable Income Taxes Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest [Abstract] Noncontrolling interests in property partnerships Noncontrolling Interest in Net Income (Loss) Limited Partnerships, Nonredeemable Noncontrolling interest—redeemable preferred units Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable Noncontrolling interest—common units of the Operating Partnership Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable Noncontrolling interest in discontinued operations - common units of the Operating Partnership Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest Net income attributable to the Company Net Income (Loss) Attributable to Parent Preferred dividends / distributions Preferred Stock Dividends, Income Statement Impact Net income attributable to the Company's common shareholders / unitholders Net Income (Loss) Available to Common Stockholders, Basic Basic earnings per common share / unit attributable to the Company's common shareholders / unitholders Earnings Per Share, Basic [Abstract] Income from continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Basic Share Discontinued operations (in dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Net income (in dollars per share / unit) Earnings Per Share, Basic Weighted average number of common shares / units outstanding Weighted Average Number of Shares Outstanding, Basic Diluted earnings per common share / unit attributable to the Company's common shareholders / unitholders Earnings Per Share, Diluted [Abstract] Income from continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Discontinued operations (in dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit) Earnings Per Share, Diluted Weighted average number of common and common equivalent shares / units outstanding (in shares / units) Weighted Average Number of Shares Outstanding, Diluted Dividends / Distributions, Per Share / Unit, Declared Common Stock, Dividends, Per Share, Declared Noncontrolling Interest [Abstract] Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Table] Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Table] Series Two Preferred Units [Member] Series Two Preferred Units [Member] Series Two Preferred Units [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Noncontrolling Interests [Member] Noncontrolling Interest [Member] OPP Units 2012 [Member] Opp Units Two Thousand And Twelve [Member] Opp Units Two Thousand And Twelve [Member] 2013 MYLTIP [Member] MYLTIP two thousand thirteen [Member] MYLTIP two thousand thirteen [Member] MYLTIP 2014 [Member] MYLTIP Two thousand fourteen [Member] MYLTIP Two thousand fourteen [Member] 2015 MYLTIP [Member] MYLTIP two thousand fifteen [Member] MYLTIP 2015 [Member] 2016 MYLTIP [Member] MYLTIP Two thousand sixteen [Member] MYLTIP 2016 [Member] OP Units [Member] Op Units [Member] OP Units [Member] Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] Operating Partnership (OP) Units (in shares) OP Units OP Units Long-Term Incentive Plan (LTIP) Units (in shares) Long Term Incentive Plan Units Long Term Incentive Plan Units Outperformance awards in LTIP Units (in shares) Outperformance Awards Long Term Incentive Plan Units Outperformance Awards Long Term Incentive Plan Units 2013 MYLTIP (in units) 2013 MYLTIP 2013 MYLTIP 2014 MYLTIP (in units) Two thousand fourteen MYLTIP 2014 MYLTIP 2015 MYLTIPS (in units) Two thousand fifteen MYLTIPS 2015 MYLTIPS 2016 MYLTIPs (in units) Two thousand sixteen MYLTIP 2016 MYLTIP Stock Option And Incentive Plan And Stock Repurchase Plan [Axis] Stock Option And Incentive Plan And Stock Repurchase Plan [Axis] Stock Option And Incentive Plan And Stock Repurchase Plan [Axis] Stock Option And Incentive Plan And Stock Repurchase Plan [Domain] Stock Option And Incentive Plan And Stock Repurchase Plan [Domain] Stock Option And Incentive Plan And Stock Repurchase Plan [Domain] 2012 OPP Units and 2013 MYLTIP Units [Member] Two thousand twelve OPP and two thousand thirteen MYLTIP [Member] 2012 OPP and 2013 MYLTIP [Member] OP Units and LTIP Units [Member] OP Units and LTIP Units [Member] OP Units and LTIP Units [Member] MYLTIP Units [Member] MYLTIP Units [Member] MYLTIP Units [Member] Unvested MYLTIP Units [Member] Unvested Two Thousand Twelve OPP Units, Two Thousand Thirteenm Fourteen, Fifteen and sixteen MYLTIP Units [Member] Unvested Two Thousand Twelve OPP Units, Two Thousand Thirteen, Fourteen, Fifteen and sixteen MYLTIP Units [Member] OP Units for redemption (in shares) OP Units redeemed for stock from LTIP Units OP Units redeemed for stock from LTIP Units Redemption of OP units issued on conversion of LTIP Units (in shares) Redemption Of OP Units Issued On Conversion Of LTIP Units Redemption Of OP Units Issued On Conversion Of LTIP Units Conversion of LTIP Units to OP Units (in units) Conversion of LTIP Units to OP Units (in units) Conversion of LTIP Units to OP Units (in units) Outperformance Awards LTIP Units distribution as percentage of OP Unit distribution prior to measurement date Outperformance Awards Long Term Incentive Plan Units Distribution As Percentage Of Op Unit Distribution Prior To Measurement Date Prior to the measurement date on February 5, 2011, 2008 OPP Units will be 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. Restriction on redemption of OP Unit to Common Stock (in years) Restriction On Redemption Restriction on redemption of OP unit to Common Stock Redemption of OP Unit equivalence to Common Stock (in shares) OP Unit Equivalence To Common Stock One OP Unit is equivalent to one common stock (share). Common units of operating partnership if converted value Common Units Of Operating Partnership If Converted Value Common Units Of Operating Partnership If Converted Value Closing price of common stock (in dollars per share) Closing price of common stock per share Common Stock Marketable Quoted Value Per Share Outperformance awards earned Outperformance awards earned Outperformance awards earned Potential maximum amount of Outperformance Awards earned (percent) Potential maximum amount of Outperformance Awards earned (percent) Potential maximum amount of Outperformance Awards earned (percent) Potential Awards Earned Potential Awards Earned Potential Awards Earned 2012 OPP Units Forfeited TwoThousandTwelveOPPUnitsForfeited 2012 OPP Unit forfeited Series Four Preferred Units Redeemed (in shares) Series Four Preferred Units Redeemed Series Four Preferred Units Redeemed Redemption of Series Four Preferred Units Redemption of Series Four Preferred Units Redemption of Series Four Preferred Units Final awards percentage of target Final awards percentage of target Final awards percentage of target Value of MYLTIP Awards Value of MYLTIP Awards Value of MYLTIP Awards 2013 MYLTIP Units Forfeited TwoThousandThirteenMYLTIPUnitsForfeited 2013 MYLTIP Units Forfeited Stock Optiona nd Incentive Plan [Abstract] Stock Optiona nd Incentive Plan [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Vesting Period [Axis] Vesting Period [Axis] Vesting Period [Axis] Vesting Period [Domain] Vesting Period [Domain] [Domain] for Vesting Period [Axis] MYLTIP vesting 2019 [Member] MYLTIP vesting 2019 [Member] MYLTIP vesting 2019 [Member] MYLTIP vesting 2020 [Member] MYLTIP vesting two thousand twenty [Member] MYLTIP vesting 2020 [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Threshold [Member] Threshold [Member] Threshold [Member] Target [Member] Target [Member] Target [Member] High [Member] High [Member] High [Member] Maximum [Member] Maximum [Member] Minimum [Member] Minimum [Member] Performance Index [Axis] Performance Index [Axis] Performance Index [Axis] Performance Index [Domain] Performance Index [Domain] Performance Index [Domain] Cohen & Steers Realty Majors Portfolio Index [Member] Cohen & Steers Realty Majors Portfolio Index [Member] Cohen & Steers Realty Majors Portfolio Index [Member] NAREIT Office Index adjusted [Member] NAREIT Office Index adjusted [Member] NAREIT Office Index adjusted [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] TSR Measurement, Years TSR Measurement, Years TSR Measurement, Years. Weighted Percentage of Index Used to Compare to TSR Weighted Percentage of Index Used to Compare to TSR Weighted Percentage of Index Used to Compare to TSR Indices Used to Compare TSR Indices Used to Compare TSR Indices Used to Compare TSR Number of Tiers Number of Tiers Number of Tiers Amount of Each Tier Amount of Each Tier Amount of Each Tier Percentage of annualized TSR for Reduction of Earned Awards Percentage of annualized TSR for Reduction of Earned Awards Percentage of annualized TSR for Reduction of Earned Awards Percentage to Cause Some Awards to be Earned Even if on a Relative Basis it Would Not Result in any Earned Awards Percentage to Cause Some Awards to be Earned Even if on a Relative Basis it Would Not Result in any Earned Awards Percentage to Cause Some Awards to be Earned Even if on a Relative Basis it Would Not Result in any Earned Awards Vesting Percentage Vesting Percentage Vesting percentage Vesting Date Vesting Date Vesting Date. Distributions Percent Before Measurement Date Distributions Percent Before Measurement Date Distributions Percent Before Measurement Date MYLTIP Value Amortized Into Earnings, Years MYLTIP Value Amortized Into Earnings, Years MYLTIP Value Amortized Into Earnings, Years Statement of Stockholders' Equity [Abstract] Statement, Equity Components [Axis] Common Stock [Member] Common Stock [Member] Preferred Stock [Member] Preferred Stock [Member] Additional Paid-In Capital [Member] Additional Paid-in Capital [Member] Dividends In Excess Of Earnings [Member] Retained Earnings [Member] Treasury Stock, At Cost [Member] Treasury Stock [Member] Accumulated Other Comprehensive (Income) Loss [Member] AOCI Attributable to Parent [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Equity, value Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Equity, shares Conversion of operating partnership units to Common Stock, shares Stock Issued During Period, Shares, Conversion of Units Conversion of operating partnership units to Common Stock, value Stock Issued During Period, Value, Conversion of Units Conversions of redeemable preferred units to common units Conversion of redeemable preferred units to common units Conversion of redeemable preferred units to common units Conversion of redeemable preferred units to common units Conversions On Series Two Preferred Units Conversions On Series Two Preferred Units Allocated net income for the year Equity Profit Loss Net Income. Dividends/distributions declared Dividends Dividends/distributions declared Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Issuance of 5.25% Series B cumulative redeemable preferred stock Preferred Cumulative Redeemable Stock Issued During Period ValueNew Issues Preferred Cumulative Redeemable Stock Issued During Period Value New Issues Sale of common stock, net of offering costs Stock Issued During Period, Shares, New Issues Sale of common stock, net of offering costs Stock Issued During Period, Value, New Issues Shares issued in connection with exchange of Exchangeable Senior Notes, shares Stock Issued During Period, Shares, Conversion of Convertible Securities Shares issued in connection with exchange of Exchangeable Senior Notes, value Stock Issued During Period, Value, Conversion of Convertible Securities Equity component of exchange of Exchangeable Senior Notes Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt Issuance of 5.25% Series B cumulative redeemable preferred stock Adjustments to Additional Paid in Capital, Increase in Carrying Amount of Redeemable Preferred Stock Shares issued pursuant to stock purchase plan, shares Stock Issued During Period, Shares, Employee Stock Purchase Plans Shares issued pursuant to stock purchase plan, value Stock Issued During Period, Value, Employee Stock Purchase Plan Net activity from stock option and incentive plan, shares Net Activity From Stock Option And Incentive Plan Shares Net Activity From Stock Option And Incentive Plan Shares. Net activity from stock option and incentive plan, value Net Activity From Stock Option And Incentive Plan Value Net activity from stock option and incentive plan, value Sale of an interest in property partnerships Sale of an interest in property partnerships Sale of an interest in property partnerships Acquisition of redeemable noncontrolling interest in property partnership Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Noncontrolling interests in property partnerships recorded upon consolidation Noncontrolling Interest, Increase from Business Combination Contributions from noncontrolling interests in property partnerships Proceeds from Noncontrolling Interests Distributions to noncontrolling interests in property partnerships Minority Interest Decrease From Distributions To Noncontrolling Interest Holders to Property Partnerships Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders. Effective portion of interest rate contracts Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Amortization of interest rate contracts Other Comprehensive Income, Other, Net of Tax Reallocation of noncontrolling interest Noncontrolling Interest, Increase from Subsidiary Equity Issuance Equity, value Equity, shares Schedule of Business Acquisitions, by Acquisition [Table Text Block] Schedule of Business Acquisitions, by Acquisition [Table Text Block] Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Restricted Stock [Member] Restricted Stock [Member] LTIP Units [Member] Ltip Units [Member] LTIP Units [Member]. 2016 MYLTIP [Member] MYLTIP two thousand and sixteen [Member] MYLTIP 2016 [Member] LTIPs (including 2012 OPP and 2013 MYLTIPS) And Restricted Stock [Member] Ltips (including vested MYLTIPS) And Restricted Stock [Member] LTIPs (including vested MYLTIPS) and Restricted Stock [Member]. LTIPs and 2016 MYLTIP Units [Member] LTIP and 2016 MYLTIP Units [Member] LTIP and 2016 MYLTIP Units [Member]. Non Qualified Stock Options [Member] Non Qualified Stock Options [Member] Non Qualified Stock Options [Member] Shares issued LTIP units issued (in shares) LTIP units issued LTIP units issued MYLTIP units issued (in shares) MYLTIP units issued MYLTIP units issued Non-qualified stock options issued Non-qualified stock options issued Non Qualified Stock Options Issued Employee and director payment per share (in dollars per share) Employee and director payment per share Employee and director payment per share Vesting annual installments Vesting Annual Installments Vesting period for grants of restricted stock and LTIP Units made in and after November 2006. Stock based Compensation Expense Allocated Share-based Compensation Expense Acceleration of Stock Basec Compensation and Stock Based Compensation Associated with Transition Agreement Acceleration of Stock Basec Compensation and Stock Based Compensation Associated with Transition Agreement Acceleration of Stock Basec Compensation and Stock Based Compensation Associated with Transition Agreement Unrecognized compensation expenses Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Weighted-average period (years) Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Common Stock, Value, Issued Common Stock, Value, Issued Employee's weighted average cost per share (in dollars per share) Common Stock Weighted Average Price Common Stock Weighted Average Price. Value of LTIP units issued Value Of LTIP Units Issued Value Of LTIP Units Issued. Per unit fair value weighted-average (in dollars per share) Weighted Average Per Unit Fair Value Weighted Average Per Unit Fair Value Expected life assumed to calculate per unit fair value per LTIP unit (years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Risk-free rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected price volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected dividend rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Method of valuation Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Method Used Weighted-average grant date fair value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted-average exercise price (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Equity [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Depository shares of Series B Cumulative Redeemable Preferred [Member] Depository shares of Series B Cumulative Redeemable Preferred [Member] Depository shares of Series B Cumulative Redeemable Preferred [Member] Atm Program [Member] Atm Program [Member] Prior Atm Program [Member] Class of Stock [Line Items] Class of Stock [Line Items] At the market stock offering program, aggregate value of common stock At The Market Stock Offering Program Aggregate Value Of Common Stock At The Market Stock Offering Program, Aggregate Value Of Common Stock At Market Stock Offering Program Maximum Length Of Sale In Years At Market Stock Offering Program Maximum Length Of Sale In Years At Market Stock Offering Program Maximum Length Of Sale In Years At the market stock offering program remaining amount available for issuance At Market Stock Offering Program Remained Available For Issuance At Market Stock Offering Program Remained Available For Issuance. Shares of Common Stock in connection with the redemption of an equal number of OP Units (in shares) Conversion of Stock, Shares Issued Shares of Common Stock upon the exercise of options to purchase Common Stock by certain employees (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Series B, Dividend Rate, Percentage Preferred Stock, Dividend Rate, Percentage Proceeds from Issuance of Series B Proceeds from Issuance of Preferred Stock and Preference Stock Ratio of depository shares to shares of Series B Preferred Stock Ratio of depository shares to shares of Series B Preferred Stock Ratio of depository shares to shares of Series B Preferred Stock Stockholders Equity / Partners Capital [Abstract] Stockholders Equity / Partners Capital [Abstract] Dividends Declared [Table Text Block] Dividends Declared [Table Text Block] Subsequent Event [Table] Subsequent Event [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Broad Run Business Park [Member] Broad Run Business Park [Member] Broad Run Business Park [Member] Colorado Center [Member] Colorado Center [Member] Colorado Center [Member] Equity Method Investee, Name [Axis] Subsequent Event [Line Items] Subsequent Event [Line Items] number of buildings number of buildings number of buildings Land acquired (in acres) Land acquired (in acres) Land acquired (in acres) Ownership Percentage Equity Method Investment, Ownership Percentage Net Rentable Area (in sf) Net Rentable Area Purchase price Purchase price, net Business Combination Recognized Identifiable Assets Acquired And Liabilities Assume, Net Business Combination Recognized Identifiable Assets Acquired And Liabilities Assume, Net Portion of Building Leased (percentage) Portion of Building Leased (percentage) Portion of Building Leased (percentage) Vehicles In Structured Parking Vehicles In Structured Parking Vehicles In Structured Parking Sale Price Of Sold Property Sale Price Of Sold Property Sale Price Of Sold Property Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Net income Other comprehensive loss: Other Comprehensive Income (Loss), Net of Tax [Abstract] Effective portion of interest rate contracts Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Amortization of interest rate contracts Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Net income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Other comprehensive income (loss) attributable to noncontrolling interests Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Comprehensive income attributable to the Company Comprehensive Income (Loss), Net of Tax, Attributable to Parent Derivative Instruments and Hedging Activities Disclosure [Abstract] Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Accumulated Other Comprehensive Income or Loss [Roll Forward] Accumulated Other Comprehensive Income or Loss [Roll Forward] Accumulated Other Comprehensive Income or Loss [Roll Forward] Beginning Balance Accumulated Other Comprehensive Income (Loss), Net of Tax Amortization of interest rate contracts Other comprehensive loss attributable to noncontrolling interests Other comprehensive loss attributable to noncontrolling interests Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest for Property Partnerships Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest for Property Partnerships Ending Balance Earnings Per Share [Abstract] Earnings Per Share / Common Unit Earnings Per Share [Text Block] Derivative [Table] Derivative [Table] Energy [Axis] Energy [Axis] Energy [Domain] Energy [Domain] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Derivative, by Nature [Axis] Derivative, by Nature [Axis] Derivative, Name [Domain] Derivative, Name [Domain] Position [Axis] Position [Axis] Position [Domain] Position [Domain] Derivative [Line Items] Derivative [Line Items] Amount of income (loss) related to the effective portion recognized in other comprehensive loss Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Amount of loss related to the effective portion subsequently reclassified to earnings (1) Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Amount of gain (loss) related to the ineffective portion and amount excluded from effectiveness testing Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Redeemable Common Units Redeemable Common Units Redeemable Common Units Basic Earnings: Net income attributable to the Company's common shareholders / unitholders Net income attributable to the Company's common shareholders / unitholders (in shares / units) Allocation of undistributed earnings to participating securities (numberator) Allocation of undistributed earnings to participating securities Allocation of undistributed earnings to participating securities Allocation of undistributed earnings to participating securities (in shares / units) Allocation of undistributed earnings to participating securities (in shares) Allocation of undistributed earnings to participating securities (in shares) Allocation of undistributed earnings to participating securities (in dollars per shares / units) Allocation of undistributed earnings to participating securities ($ per shares) Allocation of undistributed earnings to participating securities ($ per share shares) Net income attributable to the Company's common shareholders / unitholders Net Income Loss Available To Common Stockholders After Allocation of Undistributed Earnings to Participating Securities Basic Net Income Loss Available To Common Stockholders After Allocation of Undistributed Earnings to Participating Securities Basic Net income attributable to the Company'scommon shareholders / unitholders(in shares / units) Weighted Average Number Of Shares Outstanding After Allocation of Undistributed Earnings to Participating Securities Basic (in shares) Weighted Average Number Of Shares Outstanding After Allocation of Undistributed Earnings to Participating Securities Basic (in shares) Net income attributable to the Company's common shareholders / unitholders (in dollars per share / unit) Earnings Per Share After Allccation of Undistributed Earnings to Particiapting Securities Basic (dollars per share) Earnings Per Share After Allccation of Undistributed Earnings to Particiapting Securities Basic (dollars per share) Effect of Dilutive Securities: Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract] Stock Based Compensation, Income (Numerator) Dilutive Securities, Effect on Basic Earnings Per Share Stock Based Compensation, Shares / Units (Denominator) Stock Based Compensation And Exchangeable Senior Notes Shares Stock Based Compensation And Exchangeable Senior Notes Shares Stock Based Compensation, Per Share / Unit Amount (in dollars per share / unit) Dilutive Securities Per Share Amount Dilutive Securities Per Share Amount Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (Numerator) Net Income (Loss) Available to Common Stockholders, Diluted Net income attributable to the Company's common shareholders / unitholders (in shares / units) (Denominator) Noncontrolling Interest [Table] Noncontrolling Interest [Table] Fountain Square [Member] Fountain Square [Member] Fountain Square [Member] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Aggregate purchase price Aggregate purchase price Aggregate purchase price Indebtedness assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Ownership Percentage Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Fixed Price to Acquire Remaining Portion of Joint venture Fixed Price to Acquire Remaining Portion of Joint venture Fixed Price to Acquire Remaining Portion of Joint venture Payments to Acquire Businesses, Gross Payments to Acquire Businesses, Gross Ownership Percentage by the Company Noncontrolling Interest, Ownership Percentage by Parent Future Fixed Price to Acquire Remaining Portion of Joint venture Future Fixed Price to Acquire Remaining Portion of Joint venture Future Fixed Price to Acquire Remaining Portion of Joint venture Fixed Price Option Expiration Date Fixed Price Option Expiration Date Fixed Price Option Expiration Date Payments for Repurchase of Redeemable Noncontrolling Interest Payments for Repurchase of Redeemable Noncontrolling Interest Mortgage debt assumed upon acquisition of noncontrolling interest Mortgage debt assumed upon acquisition of noncontrolling interest Mortgage debt assumed upon acquisition of noncontrolling interest Accounting Policies [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Mortgages [Member] Mortgages [Member] Unsecured Debt [Member] Unsecured Debt [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Deferred Finance Costs, Net Deferred Finance Costs, Net Cumulative non-cash adjustment to the accretion of the changes in the redemption value of the noncontrolling interest Quantifying Misstatement in Current Year Financial Statements, Amount Salesforece Tower[Member] Salesforece Tower (formerly Transbay Tower) [Member] Salesforece Tower (formerly Transbay Tower) [Member] Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] Boston Properties, Inc [Member] Parent Company [Member] 505 9th Street [Member] Five zero Five Ninth Street [Member] 505 9th Street [Member] Real Estate Properties [Axis] Real Estate Property Ownership [Axis] Real Estate Properties [Domain] Real Estate Properties [Domain] Consolidated Properties [Member] Consolidated Properties [Member] Proceeds from sales of real estate Proceeds from Sale of Real Estate Held-for-investment Property partnerships Noncontrolling Interest in Limited Partnerships Partners Joint Venture Ownership Percentage Partners Joint Venture Ownership Percentage Partners Joint Venture Ownership Percentage Payments to Acquire Land Payments to Acquire Land Number of Joint Venture Partners Number of Joint Venture Partners Number of Joint Venture Partners Noncontrolling interest recorded upon consolidation maximum percentage of construction costs to allow partner to have a loan maximum percentage of construction costs to allow partner to have a loan maximum percentage of construction costs to allow partner to have a loan Portion of total costs partner can require the company to fund Portion of total costs partner can require the company to fund Portion of total costs partner can require the company to fund portion of partners equity that can be funded by the company portion of partners equity that can be funded by the company portion of partners equity that can be funded by the company ownership interest sold (percent) ownership interest sold (percent) ownership interest sold (percent) Net Contractual Sales Price Net Contractual Sales Price Net Contractual Sales Price Proceeds from sale of an interest in a real estate asset Proceeds from sale of an interest in a real estate asset Proceeds from sale of an interest in a real estate asset Portion allocation to noncontrolling interest based on carrying value of the total equity of the property prior to the sale Portion allocation to noncontrolling interest based on carrying value of the total equity of the property prior to the sale Portion allocation to noncontrolling interest based on 45% of the carrying value of the total equity of the property prior to the sale Difference between net cash proceeds received and noncontrolling interest recognized Difference between net cash proceeds received and noncontrolling interest recognized Difference between net cash proceeds received and noncontrolling interest recognized Mortgage notes payable assigned in connection with the sale of real estate Mortgage Loan Related to Property Sales Portion of project costs covered by a consteruction loan Portion of project costs covered by a consteruction loan Portion of project costs covered by a consteruction loan Costs funded (in percentage) Costs funded (in percentage) Costs funded (in percentage) Portion of costs funded (in percentage) Portion of costs funded (in percentage) Portion of costs funded (in percentage) Noncontrolling Interest Redeemable Property Partnership [Abstract] Noncontrolling Interest Redeemable Property Partnership [Abstract] Beginning Balance Temporary Equity, Carrying Amount Redeemable Interest in Property Partnerships Temporary Equity, Carrying Amount Redeemable Interest in Property Partnerships Net loss Net Loss for Redeemable interest in Property Partnership Net Loss for Redeemable interest in Property Partnership Distributions Distributions on Redeemable Property Partnership Distributions on Redeemable Property Partnership Adjustment to Reflect Redeemable Interest at Redemption Value Adjustment to Reflect Redeemable Interest at Redemption Value Adjustment to Reflect Redeemable Interest at Redemption Value Ending Balance Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Measurement Basis [Axis] Portion At Fair Value Fair Value Disclosure [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Estimated Fair Value [Member] Estimate of Fair Value Measurement [Member] Carrying Amount [Member] Reported Value Measurement [Member] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Unsecured senior notes, net Senior Notes Total Long-term Debt Debt Disclosure [Abstract] Unsecured Senior Notes Senior Notes [Text Block] Senior Notes [Text Block] Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Registrant Name Entity Registrant Name Amendment Flag Amendment Flag Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Segment Reporting [Abstract] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Statement, Business Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Business Intersegment, Eliminations [Member] Intersegment Eliminations [Member] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Preferred Stock Dividends / Distributions Noncontrolling interest-common units of the Operating Partnership Noncontrolling interest in property partnerships Impairment of Long-Lived Assets to be Disposed of Impairment of Long-Lived Assets to be Disposed of Depreciation and amortization expense Transaction costs General and administrative expense Gains on sales of real estate Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax Gains (losses) from investments in securities Gains from early extinguishments of debt Interest and other income Income from unconsolidated joint ventures Development and management services income Net Operating Income Net Operating Income The net result for the period of deducting property operating expenses from property operating revenues. Square 407 Limited Partnership [Member] Square Four Zero Seven Limited Partnership [Member] Square 407 Limited Partnership [Member]. The Metropolitan Square Associates LLC [Member] Metropolitan Square Associates Llc [Member] The Metropolitan Square Associates LLC [Member] WP Project Developer LLC [Member] Wp Project Developer Llc [Member] WP Project Developer LLC [Member] Entity Owning Land And Infrastructure Of Project [Member] Entity Owning Land And Infrastructure Of Project [Member] Entity Owning Land And Infrastructure Of Project [Member] RBP Joint Venture LLC [Member] Rbp Joint Venture Llc [Member] RBP Joint Venture LLC [Member] Boston Properties Office Value-Added Fund, L.P. [Member] Boston Properties Office Value Added Fund Lp [Member] Boston Properties Office Value Added Fund LP [Member] Annapolis Junction NFM, LLC [Member] Annapolis Junction Nfm Llc [Member] Annapolis Junction NFM LLC [Member] 2 GCT Venture LLC [Member] Two Gct Venture Llc [Member] Two GCT Venture LLC [Member]. 540 Madison Venture LLC [Member] Five Four Zero Madison Venture Llc [Member] Five Four Zero Madison Venture LLC [Member]. 125 West 55th Street Venture LLC [Member] One Two Five West Fifty Fifth Street Venture Llc [Member] One Two Five West Fifty-Fifth Street Venture LLC [Member]. 500 North Capitol LLC [Member] Five Zero Zero North Capitol Llc [Member] Five Zero Zero North Capitol LLC [Member]. 501 K Street LLC [Member] five zero one K Street LLC [Member] 501 K Street LLC [Member] Podium Developer LLC [Member] Podium Developer LLC [Member] Podium Developer LLC [Member] 1265 Main Office JV LLC [Member] One Two Six Five Main Office JV LLC [Member] 1265 Main Office JV LLC [Member] BNY Tower Holdings LLC [Member] BNY Tower Holdings LLC [Member] BNY Tower Holdings LLC [Member] Properties Name of Joint Venture Property Name of Joint Venture Property Carrying value of the Company's investments in unconsolidated joint ventures Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Number of real estate properties Number of Real Estate Properties Number of buildings under construction Number of buildings under construction Number of buildings under construction Parcels of undeveloped land Parcels of undeveloped land Parcels of undeveloped land Potential additonal payments to joint venture partner Potential additonal payments to joint venture partner Potential additonal payments to joint venture partner Minimum square footage to make a potential additional payment to joint venture partner (in sqft) Minimum square footage to make a potential additional payment to joint venture partner (in sqft) Minimum square footage to make a potential additional payment to joint venture partner (in sqft) Series Four Preferred Units [Member] series four preferred units [Member] Series Four Preferred Units [Member] Redemption Year Two Thousand Fourteen [Member] Redemption Year Two Thousand Fourteen [Member] Redemption Year Two Thousand Fourteen [Member]. Maximum Redeemable On Redemption Dates Preferred Units Maximum Redeemable On Redemption Dates Preferred Units Maximum Redeemable On Redemption Dates Preferred Units Series Two Preferred Units (in shares) Series Two Preferred Units Series Two Preferred Units Liquidation preference percentage Preferred Units Liquidation Preference Percentage Preferred Units Liquidation Preference Percentage Preferred Units Liquidation Preference Preferred Units Liquidation Preference Preferred Units Liquidation Preference First opportunity to redeem Series Four Preferred Units (in days) First opportunity to redeem Series Four Preferred Units (in days) First opportunity to redeem Series Four Preferred Units (in days) Series Four Preferred Units Released from Escrow (in shares) Series Four Preferred Units Released from Escrow Series Four Preferred Units Released from Escrow Series Four Preferred Units Elected to Redeem Series Four Preferred Units Elected to Redeem Series Four Preferred Units Elected to Redeem Operating Units liquidation preference (in dollars per share) Operating Units Conversion Rate Operating Units liquidation preference OP Units for each Preferred Unit (in shares) Op Units For Each Preferred Unit Op Units For Each Preferred Unit Series Two Preferred Units On Converted Basis Series Two Preferred Units On Converted Basis Series Two Preferred Units On Converted Basis Series Two Preferred Units Redemption Price Series Two Preferred Units Redemption Price Series Two Preferred Units Redemption Price Dates Series Two Preferred Unit Holders Can Require Redemption From Operating Partnership Dates Series Two Preferred Unit Holders Can Require Redemption From Operating Partnership Dates Series Two Preferred Unit Holders Can Require Redemption From Operating Partnership Maximum portion that may be required for redemption of total Maximum Portion That May Be Required For Redemption Of Total Maximum Portion That May Be Required For Redemption Of Total Distributions to Series Four Preferred Units (in dollars per share) Cash Distributions To Preferred Unitholders Per Unit Cash Distributions To Preferred Unitholders Per Unit Series Four Preferred Units (in shares) Series Four Preferred Units Series Four Preferred Units Series Four Preferred Units Annual Dividend Payable Rate SeriesFourPreferredUnitsAnnualDividendPayableRate Series Four Preferred Units Annual Dividend Payable Rate Number Of Holders Exercises Number Of Holders Exercises Number Of Holders Exercises Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table] Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Acquired-in-Place Lease Intangibles [Member] Leases, Acquired-in-Place [Member] Acquired Below-Market Lease Intangibles [Member] Acquired Below-Market Lease Intangibles [Member] Acquired Below-Market Lease Intangibles [Member] Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Period from April 22, 2016 through December 31, 2016 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year 2017 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Five Dividends Payable [Table] Dividends Payable [Table] Dividends [Axis] Dividends [Axis] Dividends [Domain] Dividends [Domain] special dividend [Member] special dividend [Member] special dividend [Member] Dividends Payable [Line Items] Dividends Payable [Line Items] Distributions Declared To OP And LTIP Units Per Unit Distributions Declared To OP And LTIP Units Per Unit Distributions Declared To OP And LTIP Units Per Unit Distributions Declared To MYLTIP Units Per Unit (in dollars per unit) Distributions Declared To MYLTIP Units Per Unit Distributions Declared To MYLTIP Units Per Unit Distributions made to OP and LTIP units per unit (in dollars per unit) Distributions Made To OP And LTIP Units Per Unit Distributions Made To OP And LTIP Units Per Unit Distribution paid to outperformance awards, MYLTIP Units (in dollars per unit) Distributions Made To MYLTIP Units Per Unit Distributions Made To MYLTIP Units Per Unit Stockholders' Equity / Partners' Capital Stockholders' Equity Note Disclosure [Text Block] Computation Of Basic And Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Segment Information Segment Reporting Disclosure [Text Block] Dividends Payable, Amount Per Share / Unit Dividends Payable, Amount Per Share Dividends, Per Share / Unit Common Stock, Dividends, Per Share, Cash Paid Special dividend / distribution (per share / common unit amount) Special dividend / distribution (per share / common unit amount) Special dividend / distribution (per share / common unit amount) Beginning balance NonControlling Interest Redeemable Partnership Unit Common Units Value Noncontrolling Interest Redeemable Partnership Unit Common Units Value Contributions Contributions To Noncontrolling Interest Common Units Contributions To Noncontrolling Interest Common Units. Net Income Net Income Attributable to Common Units Net Income Attributable to Common Units Distributions Distributions to noncontrolling interest common units Distributions to noncontrolling interest common units Conversion of redeemable partnership units Unearned Compensation Noncontrolling Interest, Unearned Compensation Noncontrolling Interest, Unearned Compensation. Accumulated Other Comprehensive Income (Loss) Adjustments To Reflect Redeemable Preferred Units At Redemption Value Adjustments To Reflect Redeemable Preferred Units At Redemption Value Adjustments To Reflect Redeemable Preferred Units At Redemption Value. Ending balance Mortgage Notes Payable [Abstract] Mortgage Notes Payable [Abstract] Mortgage Notes Payable Disclosure [Text Block] Mortgage Notes Payable Disclosure [Text Block] Basis Of Presentation And Summary Of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] ASSETS Assets [Abstract] Real estate, at cost (amounts includes variable interest entities (“VIEs”) at June 30, 2016) Construction in progress (amounts related to VIEs of $567,609 at June 30, 2016) Land held for future development Land Available for Development Less: accumulated depreciation (includes amounts related to VIEs at June 30, 2016) Total real estate Real Estate Investment Property, Net Cash and cash equivalents (amounts related to VIEs of $214,595 at June 30, 2016) Cash held in escrows (amounts related to VIEs of $3,527 at June 30, 2016) Investments in securities Marketable Securities Tenant and other receivables (amounts related to VIEs of $19,719 at June 30, 2016) Accrued rental income (amounts related to VIEs of $220,277 at June 30, 2016) Deferred charges, net (amounts related to VIEs of $320,317 at June 30, 2016) Prepaid expenses and other assets (amounts related to VIEs of $84,345 at June 30, 2016) Investments in unconsolidated joint ventures Total assets Assets LIABILITIES AND EQUITY / CAPITAL Liabilities and Equity [Abstract] Liabilities: Liabilities [Abstract] Mortgage notes payable, net (amounts related to VIEs of $2,046,828 at June 30, 2016) Unsecured line of credit Long-term Line of Credit Mezzanine notes payable (amounts related to VIEs of $307,797 at June 30, 2016) Outside members' notes payable (amounts related to VIEs of $180,000 at June 30, 2016) Other Notes Payable Outside members' notes payable Notes Payable, Related Parties, Noncurrent Accounts payable and accrued expenses (amounts related to VIEs of $109,038 at June 30, 2016) Dividends and distributions payable Dividends Payable Accrued interest payable (amounts related to VIEs of $144,327 at June 30, 2016) Other liabilities (amounts related to VIEs of $195,437 at June 30, 2016) Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Noncontrolling interest: Temporary Equity [Abstract] NonControlling Interest Redeemable Partnership Series Four Units Preferred Units Value NonControlling Interest Redeemable Partnership Series Four Units Preferred Units Value NonControlling Interest Redeemable Partnership Series Four Units Preferred Units Value Redeemable partnership units—17,184,629 and 16,097,473 common units and 912,605 and 1,831,714 long term incentive units outstanding at redemption value at June 30, 2016 and December 31, 2015, respectively NonControlling Interest Redeemable Partnership Units Common Units Value Amount of Noncontrolling interest redeemable partnership common units. Redeemable preferred units of the Operating Partnership Redeemable Noncontrolling Interest, Equity, Carrying Amount Redeemable interest in property partnership Equity / Capital Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Excess stock, $0.01 par value, 150,000,000 shares authorized, none issued or outstanding Excess Stock Value Excess Stock Value Preferred stock, $.01 par value, 50,000,000 shares authorized Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract] 5.25% Series B cumulative redeemable preferred stock / unit liquidation preference $2,500 per share / unit, 92,000 shares / units authorized, 80,000 shares / units issued and outstanding at June 30, 2016 and December 31, 2015 Preferred Stock, Value, Issued Common stock, $0.01 par value, 250,000,000 shares authorized, 153,753,830 and 153,658,866 issued and 153,674,930 and 153,579,966 outstanding at June 30, 2016 and December 31, 2015, respectively Additional paid-in capital Additional Paid in Capital Dividends in excess of earnings Retained Earnings (Accumulated Deficit) Treasury common stock at cost, 78,900 shares at June 30, 2016 and December 31, 2015 Treasury Stock, Value Accumulated other comprehensive loss Total stockholders’ equity attributable to Boston Properties, Inc. Stockholders' Equity Attributable to Parent Noncontrolling interests: Noncontrolling Interest Items [Abstract] Common units of the Operating Partnership Noncontrolling Interest in Operating Partnerships Boston Properties Limited Partnership partners’ capital—1,717,722 and 1,715,092 general partner units and 151,957,208 and 151,864,874 limited partner units outstanding at June 30, 2016 and December 31, 2015, respectively Partners' Capital Total equity / capital Total liabilities and equity / capital Liabilities and Equity Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Boston Properties Inc Parent [Member] Depositary [Axis] Depositary [Axis] Depositary [Axis] Depositary [Domain] Depositary [Domain] [Domain] for Depositary [Axis] depositary shares [Member] depositary shares [Member] depositary shares [Member] Series B Preferred Units [Member] Series B Preferred Units [Member] Series B Preferred Units [Member] Commercial Real Estate Properties [Member] Commercial Real Estate [Member] Total Properties Under Construction [ Member] Properties Under Construction [Member] Properties Under Construction [Member]. Total Office Properties [ Member] Total Office Properties [Member] Total Office Properties [Member]. Class A Office Properties [Member] Class A Office Properties [Member] Class A Office Properties [Member]. Office Properties Under Construction [ Member] Office Properties Under Construction [Member] Office Properties Under Construction [Member]. Office Technical Properties [Member] Office Technical Properties [Member] Office/Technical Properties [Member]. Hotel Property [ Member] Hotel Property [Member] Hotel Property [Member]. Retail Properties [ Member] Retail Properties [Member] Retail Properties [Member]. Retail Properties Under Construction [Member] Retail Properties Under Construction [Member] Retail Properties Under Construction [Member] Residential Properties [Member] Residential Real Estate [Member] Residential Properties Under Construction [Member] Residential Properties Under Construction [Member] Residential Properties Under Construction [Member] Real Estate Properties [Line Items] Real Estate Properties [Line Items] General and limited partnership interest in the operating partnership (percent) Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest Restriction on redemption of OP units from date of issuance (years) Restriction On Redemption Of OP Units From Date Of Issuance In Years Restriction On Redemption Of OP Units From Date Of Issuance In Years in lieu of a cash redemption OP unit to Common Stock conversion (in shares) in lieu of a cash redemption OP unit to Common Stock conversion in lieu of a cash redemption OP unit to Common Stock conversion One OP unit is equivalent to one share of Common Stock (in shares) Common Stock Conversion Rate Common Stock Conversion Rate OP unit conversion rate (in shares) OP Unit Conversion Rate OP Unit Conversion Rate. Number Of Series Of Preferred Units Outstanding Number Of Series Of Preferred Units Outstanding Number Of Series Of Preferred Units Outstanding. Number of real estate properties Area of undeveloped land parcels owned (in acres) Area Of Undeveloped Land Area Of Undeveloped Land Senior Notes [Member] Senior Notes [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Unsecured Senior Notes 5.967% Ten Year Unsecured Senior Notes Five Point Nine Six Seven Percent [Member] Ten Year Unsecured Senior Notes Five Point Nine Six Seven Percent [Member]. Unsecured Senior Notes 5.708% Ten Year Unsecured Senior Notes Five Point Seven Zero Eight Percent [Member] Ten Year Unsecured Senior Notes Five Point Seven Zero Eight Percent [Member] Unsecured Senior Notes 4.289% Ten Year Unsecured Senior Notes Four Point Two Eight Nine Percent [Member] Ten Year Unsecured Senior Notes Four Point Two Eight Nine Percent [Member]. Unsecured Senior Notes 3.853% Seven Year Unsecured Senior Notes Three Point Eight Five Three Percent [Member] Seven Year Unsecured Senior Notes Three Point Eight Five Three Percent [Member] Unsecured Senior Notes 3.954% Eleven Year Unsecured Senior Notes Three Point Nine Five Four Percent [Member] Eleven Year Unsecured Senior Notes Three Point Nine Five Four Percent [Member] Unsecured Senior Notes 3.279% Ten and Half Year Unsecured Senior Notes Three Point Two Seven Nine Percent [Member] Ten and Half Year Unsecured Senior Notes Three Point Two Seven Nine Percent [Member] Unsecured Senior Notes 3.916% Ten and Half Year Unsecured Senior Notes Three Point Nine One Six Percent [Member] Ten and Half Year Unsecured Senior Notes Three Point Nine One Six Percent [Member] Unsecured Senior Notes 3.766% Ten year unsecured senior note three point seven six six percent [Member] Ten year unsecured senior note t3.766%[Member] Coupon/Stated Rate Debt Instrument, Interest Rate, Stated Percentage Effective Rate Debt Instrument, Interest Rate, Effective Percentage Principal Amount Long-term Debt, Gross Maturity Date Debt Instrument, Maturity Date Net unamortized discount Debt Instrument, Unamortized Discount Deferred Finance Costs, Net Total Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Statement, Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Boston [Member] Boston [Member] Boston [Member] New York [Member] New York [Member] New York [Member] San Francisco [Member] San Francisco [Member] San Francisco [Member] Washington, DC [Member] Washington D C [Member] Washington D C [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Rental Revenue: Office Rental Revenue Class A Office Rental Revenue Class A Office Rental Revenue: Residential Rental Revenue Residential Rental Revenue Residential. Rental Revenue: Hotel Total revenue Rental Revenue Total Rental Revenue Total Rental Revenue: % of Grand Totals Percentage Of Total Revenue These are percentages not monetary value Rental Expenses: Office Rental Expenses Class Office Rental Expenses Class Office Rental Expenses: Residential Rental Expenses Residential Rental Expenses Residential. Rental Expenses: Hotel Rental Expenses: Total Rental Expenses Operating Expenses Total Rental Expenses Operating Expenses Total. Rental Expenses: % Of Grand Totals Percentage Of Total Rental Expenses Percentage Of Total Rental Expenses. Net operating Income Operating Income Loss From Reportable Segments Operating Income Loss From Reportable Segments Net operating Income: % of Grand Totals Percentage Of Total Net Operating Income Percentage Of Total Net Operating Income Investments In Unconsolidated Joint Ventures Equity Method Investments [Table Text Block] Schedule Of Balance Sheets Of The Unconsolidated Joint Ventures [Text Block] Schedule Of Balance Sheets Of The Unconsolidated Joint Ventures [Text Block] Schedule Of Balance Sheets Of The Unconsolidated Joint Ventures [Text Block] Statements Of Operations Of The Joint Ventures Schedule Of Statements Of Operations Of The Unconsolidated Joint Ventures [Text Bock] Schedule Of Statements Of Operations Of The Unconsolidated Joint Ventures [Text Bock] Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Senior Notes Schedule of Senior Notes [Table Text Block] Schedule of Senior Notes [Table Text Block] Unsecured Senior Notes [Abstract] Unsecured Senior Notes [Abstract] Maximum Leverage Ratio Maximum Leverage Ratio Maximum Leverage Ratio Maximum Secured Debt Leverage Ratio Maximum Secured Debt Leverage Ratio Maximum Secured Debt Leverage Ratio Minimum Interest Coverage Ratio Minimum Interest Coverage Ratio Minimum Interest Coverage Ratio Minimum Unencumbered Asset Value Percentage Of Unsecured Debt Minimum Unencumbered Asset Value Percentage Of Unsecured Debt Minimum Unencumbered Asset Value Percentage Of Unsecured Debt Senior Notes Pricing Senior Notes Pricing Note Price Percentage Of Principal Amount Proceeds from Issuance of Unsecured Debt Proceeds from Issuance of Unsecured Debt Commitments And Contingencies Disclosure [Table] Commitments And Contingencies Disclosure [Table] Commitments and Contingencies Disclosure [Table] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] 200 Clarendon Street [Member] Two Hundred Clarendon Street [Member] 200 Clarendon Street [Member] 601 Lexington Avenue [Member] Six Zero One Lexington Avenue [Member] Six Zero One Lexington Avenue [Member] Gain Contingencies, Nature [Axis] Gain Contingencies, Nature [Axis] Gain Contingency, Nature [Domain] Gain Contingency, Nature [Domain] Lehman [Member] Lehman [Member] Lehman [Member] 767 Venture, LLC [Member] Seven Six Seven Venture Llc [Member] Seven Six Seven Venture LLC [Member] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Letter of credit and performance obligations Letter Of Credit And Performance Obligation Letter Of Credit And Performance Obligation Maximum funding obligation Guarantor Obligations, Maximum Exposure, Undiscounted Guarantee Obligation Related To Tenant Re-Leasing Costs Guarantee Obligation Related To Tenant Re-Leasing Costs Guarantee Obligation Related To Tenant Re-Leasing Costs Bankruptcy claim, amount filed by general creditor Bankruptcy claim, amount filed by general creditor Bankruptcy claim, amount filed by general creditor Bankruptcy claim amount allowed by court to creditor Bankruptcy claim amount allowed by court to creditor Bankruptcy claim amount allowed by court to creditor Bankruptcy claim, price on the private market Bankruptcy claim, price on the private market Bankruptcy claim, price on the private market Bankruptcy claim, denominator used to evaluate claim price amount Bankruptcy claim, denominator used to evaluate claim price amount Bankruptcy claim, denominator used to evaluate claim price amount Bankruptcy Claims, Amount of Claims Filed Bankruptcy Claims, Amount of Claims Filed Property insurance program per occurrence limits Insurance Policy Limit Insurance Policy Limit Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP Coverage for acts of Terrorism certified under TRIA in excess of amount provided by NYXP, LLC, as a direct insurer Coverage For Acts Of Terrorism Under TRIA Coverage For Acts Of Terrorism Under TRIA Coverage for acts of terrorism certified under TRIA Coverage for acts of Terrorism certified under TRIA provided by NYXP, LLC, as a direct insurer The property insurance program per occurrence limits for 767 Fifth Avenue are $1.625 billion, including coverage for acts of terrorism certified under TRIA, with $1.375 billion of coverage for losses in excess of $250 million being provided by NYXP, LLC, as a direct insurer. Per occurrence limit for NBCR Coverage Per occurrence limit for NBCR Coverage Per occurrence limit for NBCR Coverage Value of program trigger Program Trigger Value Program Trigger Value Coinsurance of program trigger Program Trigger Coinsurance Program Trigger Coinsurance Deductible in insurance as a percentage of the value of the affected property, San Francisco Earthquake Deductible Insurance Percentage Of Value Of The Affected Property San Francisco Earthquake Deductible Insurance Percentage Of Value Of The Affected Property San Francisco Per occurrence limit of the earthquake insurance which covers San Francisco region Per Occurrence Limit Of Earth Quake Insurance San Francisco Per Occurrence Limit Of Earth Quake Insurance San Francisco Annual aggregate limit of the earthquake insurance which covers San Francisco region Annual Aggregate Limit Of Earth Quake Insurance San Francisco Annual Aggregate Limit Of Earth Quake Insurance San Francisco Amount of earthquake insurance provided by IXP, LLC as direct insurer San Francisco Amount Of Earthquake Insurance Provided By IXP LLC As Direct Insurer San Francisco Amount Of Earthquake Insurance Provided By IXP LLC As Direct Insurer San Francisco. Earthquake Coverage Included in Builders Risk Policy for 680 Folsom Earthquake Coverage Included in Builders Risk Policy for 680 Folsom Earthquake Coverage Included in Builders Risk Policy for 680 Folsom Earthquake Coverage Included In Builders Risk Policy For 535 Mission Earthquake Coverage Included In Builders Risk Policy For 535 Mission Earthquake Coverage Included In Builders Risk Policy For 535 Mission Earthquake Coverage Included In Builders Risk Policy For Salesforce Tower Earthquake Coverage Included In Builders Risk Policy For Improvements for Salesforce Tower Earthquake Coverage Included In Builders Risk Policy For Improvements for Salesforce Tower Operating partnership guarantee to cover liabilities of IXP Operating partnership guarantee to cover liabilities of subsidiary Operating partnership guarantee to cover liabilities of subsidiary Bankruptcy Claims, Amount of Claims Settled Bankruptcy Claims, Amount of Claims Settled Bankruptcy remaining claim amount allowed by court to creditor Bankruptcy remaining claim amount allowed by court to creditor Bankruptcy remaining claim amount allowed by court to creditor Bankruptcy remaining claim amount based on a privately quoted value Bankruptcy remaining claim amount based on a privately quoted value Bankruptcy remaining claim amount based on a privately quoted value Secured Debt [Member] Secured Debt [Member] Repayments of Secured Debt Repayments of Secured Debt Hedging Issuer [Axis] Hedging Issuer [Axis] Hedging Issuer [Axis] Hedging Issuer [Domain] Hedging Issuer [Domain] [Domain] for Hedging Issuer [Axis] 767 Fifth Partners LLC [Member] Seven six seven Fifth Partners LLC [Member] 767 Fifth Partners LLC [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Swap [Member] Interest Rate Swap [Member] Number of interest rate swap agreements entered into (swap contracts) Number of interest rate swap agreements entered into Number of interest rate swap agreements entered into Term of anticipated mortgage loan (in years) Term of anticipated mortgage loan (in years) Term of anticipated mortgage loan (in years) Maximum period of hedging exposure to the variability in future cash flows for forecasted transactions (in years) Maximum period of hedging exposure to the variability in future cash flows for forecasted transactions (in years) Maximum period of hedging exposure to the variability in future cash flows for forecasted transactions (in years) Derivative, Net Liability Position, Aggregate Fair Value Derivative, Net Liability Position, Aggregate Fair Value Assets Needed for Immediate Settlement, Aggregate Fair Value Assets Needed for Immediate Settlement, Aggregate Fair Value Amount of loss related to the effective portion recognized in accumulated other comprehensive loss Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion Average Fixed Interest Rate Derivative, Average Fixed Interest Rate Notional Amount Derivative, Notional Amount Estimated current balance held in Accumulated Other Comprehensive Loss to be reclassified into earnings within the next twelve months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Schedule Of Segment Information By Geographic Area And Property Type Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule Of Reconciliation Of Net Operating Income To Net Income Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Real estate and development in process, net Other assets Other Assets Total assets Equity Method Investment, Summarized Financial Information, Assets Liabilities and Members'/Partners' Equity [Abstract] Members'/Partners' equity Equity Method Investment, Summarized Financial Information, Equity Excluding Noncontrolling Interests Company's share of equity Company Share Of Equity Company Share Of Equity Basis differentials Basis Differentials 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. Carrying value of the Company's investments in unconsolidated joint ventures Redeemable Preferred Units [Member] Redeemable Preferred Units [Member] Redeemable Preferred Units [Member] Activity of Noncontrolling Interests [Roll Forward] Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward] Beginning Balance Issuance of redeemable preferred units (Series Four Preferred Units) Issuance of redeemable preferred units Issuance of redeemable preferred units Net Income Distributions Distributions to Preferred Units Distributions to Preferred Units Redemption of redeemable preferred units (Series Four Preferred Units) Redemption of redeemable preferred units Redemption of redeemable preferred units Ending Balance Stock Option and Incentive Plan Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Property Partnerships Member Property Partnerships Member Property Partnerships [Member] Beginning Balance Capital contributions Net income Accumulated other comprehensive income (loss) Distributions Minority Interest Distributions Limited Partnerships Minority Interest Distributions Limited Partnerships. Ending Balance Equity Method Investments and Joint Ventures [Abstract] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Construction Loans [Member] Construction Loans [Member] Annapolis Junction Building Seven [Member] Annapolis Junction Building Seven [Member] Annapolis Junction Building Seven [Member] Annapolis Junction Buidling One [Member] Annapolis Junction Buidling One [Member] Annapolis Junction Buidling One [Member] Secured Debt Number of extensions Number of extensions Number of extensions Carrying Value Of Indebtedness And Corresponding Estimate Of Fair Value Fair Value, by Balance Sheet Grouping [Table Text Block] Statement of Partners' Capital [Abstract] Beginning Balance Aggregate Partners Capital (inclusive of Series B Preferred Units) Aggregate Partners Capital (inclusive of Series B Preferred Units) Contributions Partners' Capital Account, Contributions Net income allocable to general and limited partner units Net income allocable to general and limited partner units Net Income Allocable To General And Limited Partner Units Distributions Partners' Capital Account, Distributions Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Loss Allocable To General And Limited Partner Units Accumulated Other Comprehensive Loss Allocable To General And Limited Partner Units. Unearned compensation Partners' Capital Account, Deferred Compensation Conversion of redeemable partnership units Partners' Capital Account, Exchanges and Conversions Adjustment to reflect redeemable partnership units at redemption value Partners' Capital Account, Redemptions Ending Balance Investments In Unconsolidated Joint Ventures Equity Method Investments and Joint Ventures Disclosure [Text Block] Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Non-cash compensation expense Share-based Compensation Income from unconsolidated joint ventures Gains on consolidation of joint ventures Distributions of net cash flow from operations of unconsolidated joint ventures Proceeds from Equity Method Investment, Dividends or Distributions Gains from investments in securities Gain (Loss) on Sale of Investments Non-cash portion of interest expense Paid-in-Kind Interest Gains on sales of real estate Gain (Loss) on Sale of Properties Gains from early extinguishments of debt Non Cash Portion Of Loss From Early Extinguishment Of Debt Non Cash Portion Of Loss From Early Extinguishment Of Debt Gains on sale of real estate from discontinued operations Gain (Loss) on Disposition of Real Estate, Discontinued Operations Gain on forgiveness of debt from discontinued operations Discontinued Operation, Gain (Loss) on Forgiveness Of Debt Amount of gain (loss), not previously recognized, resulting from the forgiveness of debt pertaining to a real estate property. Impairment loss from discontinued operations Change in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Cash held in escrows Increase (Decrease) in Restricted Cash for Operating Activities Tenant and other receivables, net Increase (Decrease) in Accounts Receivable Accrued rental income, net Straight Line Rent Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Accrued interest payable Increase (Decrease) in Interest Payable, Net Other liabilities Increase (Decrease) in Other Operating Liabilities Tenant leasing costs Tenant leasing costs Tenant leasing costs Total adjustments Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Acquisition of real estate Payments to Acquire and Develop Real Estate Construction in progress Construction and Development Costs Building and other capital improvements Payments for Capital Improvements Tenant improvements Payments for Tenant Improvements Proceeds from sales of real estate placed in escrow Increase in Restricted Cash Proceeds from sales of real estate released from escrow Decrease in Restricted Cash Cash placed in escrow for land sale contracts Cash placed in escrow for land sale contracts Cash placed in escrow for land sale contracts Cash released from escrow for land sale contracts Cash released from ecrow for land sale contracts Cash released from escrow for land sale contracts Cash released from escrow for investing activities Increase (Decrease) in Restricted Cash Deposits on real estate Payments for (Proceeds from) Deposits on Real Estate Acquisitions Capital contributions to unconsolidated joint ventures Payments to Acquire Equity Method Investments Capital distributions from unconsolidated joint ventures Investments in securities, net Payments to Acquire Marketable Securities Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Repayments of mortgage notes payable Proceeds from unsecured senior notes Redemption of unsecured senior notes Repayments of Unsecured Debt Proceeds from real estate financing transaction Proceeds from real estate transaction Proceeds from real estate transaction Payments on real estate financing transactions Payments on real estate transaction Payments on real estate transaction Deferred financing costs Payments of Financing Costs Net proceeds from preferred stock issuance Net proceeds from ATM stock issuances At Market Stock Offering Program Net Proceeds At Market Stock Offering Program Net Proceeds Net proceeds from equity transactions Proceeds from Issuance or Sale of Equity Redemption of preferred units Payments for redemption of preferred units Payments for redemption of preferred units Dividends and distributions Payments of Dividends Contributions from noncontrolling interests in property partnerships Proceeds from (Payments to) Noncontrolling Interests Distributions to noncontrolling interests in property partnerships Payments to Noncontrolling Interests Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Supplemental disclosures: Supplemental Cash Flow Information [Abstract] Cash paid for interest Interest Paid Interest capitalized Interest Costs Capitalized Non-cash investing and financing activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Write off of fully depreciated real estate Write off of fully depreciated real estate Write off of fully depreciated real estate Additions to real estate included in accounts payable and accrued expenses Additions to real estate included in accounts payable and accrued expenses Additions to real estate included in accounts payable and accrued espenses. Real estate and related intangibles recorded upon consolidation Aggregate Consideration Due to Consolidation Aggregate Consideration Due to Consolidation Debt recorded upon consolidation Total debt recorded upon consolidation Total debt recorded upon consolidation Working capital recorded upon consolidation Working capital recorded upon consolidation Working capital recorded upon consolidation Investment in unconsolidated joint venture eliminated upon consolidation investment in unconsolidated joint venture elminated upon consolidation investment in unconsolidated joint venture elminated upon consolidation Mortgage note payable extinguished through foreclosure Transfer Mortgage Payable Real estate transferred upon foreclosure Real Estate Owned, Transfer from Real Estate Owned Land improvements contributed by noncontrolling interest in property partnership Land improvements contributed by noncontrolling property partnership Land improvements contributed by noncontrolling property partnership Preferred Units Issued In Connection With Acquisition Of Real Estate Preferred Units Issued In Connection With Acquisition Of Real Estate Preferred Units Issued In Connection With Acquisition Of Real Estate Dividends and distributions declared but not paid Issuance of common stock in connection with the exchange of exchangeable senior notes Conversions of noncontrolling interests to stockholders’ equity Conversions of noncontrolling interests to Stockholders' Equity Conversions of noncontrolling interests to Stockholders' Equity Issuance of restricted securities to employees Issuance Of Restricted Units To Employees And Directors Issuance Of Restricted Units To Employees And Directors Issuance of restricted securities to employees Issuance of restricted securities to employees and directors Issuance of restricted securities to employees and directors Recent Accounting Pronouncements [Abstract] Recent Accounting Pronouncements [Abstract] Recent Accounting Pronouncement [Policy Text Block] Recent Accounting Pronouncement [Policy Text Block] Recent Accounting Pronouncement [Policy Text Block] Schedule Of redeemable preferred units Schedule Of Redeemable Preferred Units of the Operating Partnership [Table Text Block] Schedule Of Redeemable Preferred Units of the Operating Partnership [Table Text Block] Schedule of Redeemable Interest in Property Partnerships [Table Text Block] Schedule of Redeemable Interest in Property Partnerships [Table Text Block] Schedule of Redeemable Interest in Property Partnerships [Table Text Block] Distributions Declared to OP, LTIP, OPP and MYLTIP Units [Table Text Block] Schedule Of Noncontrolling Interest Common Units [Table Text Block] Schedule Of Noncontrolling Interest Common Units [Table Text Block] Schedule Of Noncontrolling Interest Common Units [Table Text Block] Schedule Of Noncontrolling Interest Property Partnerships [Table Text Block] Schedule Of Noncontrolling Interest Property Partnerships [Table Text Block] Schedule Of Noncontrolling Interest Property Partnerships [Table Text Block] Derivative Instruments and Hedging Activities [Text Block] Derivative Instruments and Hedging Activities Disclosure [Text Block] Interest Rate Swap Range 2.129% - 2.571% [Member] Interest Rate Swap Range two point one two nine percent to two point five seven one percent [Member] Interest Rate Swap Range two point one two nine percent to two point five seven one percent [Member] Interest Rate Swap Range 2.336% - 2.950% [Member] Interest Rate Swap Range two point three three six percent to two point nine five zero percent [Member] Interest Rate Swap Range two point three three six percent to two point nine five zero percent [Member] Interest Rate Swap Range 2.348% - 2.571% [Member] Interest Rate Swap Range two point three four eight percent to two point five seven one percent [Member] [Member] Interest Rate Swap Range two point three four eight percent to two point five seven one percent Interest Rate Swap Range 2.129% - 2.325% [Member] Interest Rate Swap Range two point one two nine percent to two point three two five percent [Member] Interest Rate Swap Range two point one two nine percent to two point three two five percent [Member] Interest Rate Swap Range 2.677% - 2.950% [Member] Interest Rate Swap Range two point six seven seven percent to two point nine five zero percent [Member] Interest Rate Swap Range two point six seven seven percent to two point nine five zero percent [Member] Interest Rate Swap Range 2.336% - 2.430% [Member] Interest Rate Swap Range two point three three six percent to two point four three zero percent [Member] Interest Rate Swap Range two point three three six percent to two point four three zero percent [Member] Derivative Liability, Notional Amount Derivative Liability, Notional Amount Derivative Asset, Notional Amount Derivative Asset, Notional Amount Derivative, Lower Fixed Interest Rate Range Derivative, Lower Fixed Interest Rate Range Derivative, Higher Fixed Interest Rate Range Derivative, Higher Fixed Interest Rate Range Fair Value Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Future development [Member] Future development [Member] Future development [Member] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Domain] Lease Arrangement, Type [Domain] Terminated lease at 250 West 55thStreet in NYC [Member] Terminated lease at two fifty West fifty fifth Street in NYC [Member] Terminated lease at 250 West 55th Street in NYC [Member] 601 Massachusetts Avenue [Member] Six Zero One Massachusetts Avenue [Member] 601 Massachusetts Avenue [Member] 804 Carnegie Center [Member] eight zero four carnegie center [Member] 804 Carnegie Center [Member] 10 CityPoint [Member] Ten CityPoint [Member] 10 CityPoint [Member] 415 Main Street [Member] Four One Five Main Street [Member] Four One Five Main Street [Member] Net income (loss) Revenues Noncontrolling Interests Noncontrolling Interest Disclosure [Text Block]