Trading Arrangements, by Individual
Trading Arrangements, by Individual [Table]
Hotel [Member]
Hotel [Member]
Trading Arrangement:
Trading Arrangement [Axis]
Maximum [Member]
Maximum [Member]
Portion at Fair Value Measurement [Member]
Portion at Fair Value Measurement [Member]
Title of 12(b) Security
Title of 12(b) Security
Subsequent Event [Member]
Subsequent Event [Member]
Diluted Earnings: Net income (Loss) attributable to the Company
Net Income (Loss) Available to Common Stockholders, Diluted
Carrying Amount [Member]
Reported Value Measurement [Member]
Derivative Instruments, Gain (Loss) [Table]
Derivative Instruments, Gain (Loss) [Table]
Debt, Weighted Average Interest Rate
Debt, Weighted Average Interest Rate
Adjustment to Compensation, Amount
Adjustment to Compensation Amount
Shares of Common Stock issued in connection with redemption of an equal number of OP Units (in shares)
Conversion of Stock, Shares Issued
6.162% unsecured senior notes
Six Point One Six Two Percent [Member]
Six Point One Six Two Percent
Segment Reporting [Abstract]
Segment Reporting [Abstract]
Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense
Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense [Table Text Block]
MYLTIP 2026
MYLTIP Two thousand Twenty Six [Member]
MYLTIP Two thousand Twenty Six
Long Term Debt, Renewal Term
Long Term Debt, Renewal Term
Long Term Debt, Renewal Term
Lessee, Finance Leases
Lessee, Finance Leases [Text Block]
Derivative Instrument [Axis]
Derivative Instrument [Axis]
Write-off of fully depreciated real estate
Write off of fully depreciated real estate
Write off of fully depreciated real estate
Consolidated Entities [Axis]
Consolidated Entities [Axis]
Proceeds from mortgage notes payable
Proceeds from Secured Notes Payable
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
3.766% unsecured senior notes
Three point seven six six percent unsecured senior notes [Member]
3.766% unsecured senior notes
Construction Loan
Construction Loan
Common stock available for issuance, target
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized, Target
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized, Target
Leases [Abstract]
Leases [Abstract]
Other comprehensive income (loss) :
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Intangible Asset, Finite-Lived, Acquired [Line Items]
Intangible Asset, Finite-Lived, Acquired [Line Items]
Consolidated Entities [Domain]
Consolidated Entities [Domain]
Distributions to noncontrolling interests in property partnerships
Payments to Noncontrolling Interests
Redeemable Common Units
Redeemable Common Units
Redeemable Common Units
Company's Share [Member]
Company's Share [Member]
Company's Share [Member]
Acquisitions of real estate
Payments to Acquire Commercial Real Estate
Common Stock, Par or Stated Value Per Share
Common Stock, Par or Stated Value Per Share
Mortgage notes payable recorded upon consolidation
Loans Assumed
2025 OPP
Two Zero Two Five OPP [Member]
2025 OPP
Outstanding Aggregate Erroneous Compensation Amount
Outstanding Aggregate Erroneous Compensation Amount
Notes Receivables [Member]
Notes Receivable [Member]
Construction Loans
Construction Loans [Member]
Accounting Standards Update [Axis]
Accounting Standards Update [Axis]
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $8,539,478 and $8,005,124 at September 30, 2026 and December 31, 2025, respectively)
Real Estate Investment Property, at Cost
Real Estate Investment Property, at Cost
Schedule of Derivative Assets at Fair Value [Table Text Block]
Schedule of Derivative Assets at Fair Value [Table Text Block]
Entity Address, City or Town
Entity Address, City or Town
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Final awards percentage of target
Final awards percentage of target
Final awards percentage of target
Sales-type lease receivable, net
Sales-type Lease, Lease Receivable
Statement of Financial Position [Abstract]
Statement of Financial Position [Abstract]
Op units and LTIP units
Op units and LTIP units [Member]
Op units and LTIP units
Peer Group Total Shareholder Return Amount
Peer Group Total Shareholder Return Amount
Capital distributions from unconsolidated joint ventures
Proceeds from Equity Method Investment, Distribution, Return of Capital
Total Shareholder Return Vs Peer Group
Total Shareholder Return Vs Peer Group [Text Block]
Entity Well-known Seasoned Issuer
Entity Well-known Seasoned Issuer
Other comprehensive income (loss)
Other Comprehensive Income (Loss), Net of Tax
Non-Rule 10b5-1 Arrangement Terminated
Non-Rule 10b5-1 Arrangement Terminated [Flag]
BXP Inc. [Member]
Parent Company [Member]
2020-2022 Vested MYLTIPs [Member]
2020-2022 Vested MYLTIPs [Member]
2020-2022 Vested MYLTIPs
Total Capital [Member]
Capital [Member]
Capital [Member]
Name of Property [Axis]
Name of Property [Axis]
Subsequent Event Type [Axis]
Subsequent Event Type [Axis]
Adjustments to Additional Paid in Capital, Other
Adjustments to Additional Paid in Capital, Other
Effective portion of interest rate contracts
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-Term Debt Instruments [Table]
Debt Instrument, Description of Variable Rate Basis
Debt Instrument, Description of Variable Rate Basis
Gateway Portfolio Holdings LLC and Seven Seven Five Zero Wisconsin Avenue LLC
Gateway Portfolio Holdings LLC and Seven Seven Five Zero Wisconsin Avenue LLC [Member]
Gateway Portfolio Holdings LLC and Seven Seven Five Zero Wisconsin Avenue LLC
Schedule Of Segment Information By Geographic Area And Property Type
Segment Reporting [Table Text Block]
Use of Estimates in the Preparation of Financial Statements
Use of Estimates, Policy [Policy Text Block]
Related Party [Axis]
Related and Nonrelated Parties [Axis]
Investment in unconsolidated joint ventures eliminated upon consolidation
Investment in unconsolidated joint ventures eliminated upon consolidation
Investment in unconsolidated joint ventures eliminated upon consolidation
Repayments of unsecured line of credit
Repayments of Lines of Credit
Rental Revenue Total
Rental Revenue Total
Rental Revenue Total
Rental Revenue Total
Lessee, Operating Lease, Liability, Maturity
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]
Non-cash investing and financing activities:
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Net activity from contributions and unearned compensation, value
Partners' Capital Account, Contributions
Document Period End Date
Document Period End Date
Boston Properties Limited Partnership
Subsidiaries [Member]
Distributions Payable, Amount Per Unit
Dividends Payable, Amount Per Share / Unit
Dividends Payable, Amount Per Share
Preferred stock / units, shares / units outstanding (in shares / units)
Preferred Stock, Shares Outstanding
Debt - Total loan amount
Debt Instrument, Face Amount
Shady Grove Parcel Three
Shady Grove Parcel Three [Member]
Shady Grove Parcel Three
Basic earnings per common share / unit attributable to the Company
Basic Earnings:
Earnings Per Share, Basic [Abstract]
Debt Instrument, Interest Rate, Effective Percentage
Debt Instrument, Interest Rate, Effective Percentage
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships
Proceeds from Noncontrolling Interests
Lessor, Operating Leases [Text Block]
Lessor, Operating Leases [Text Block]
Coinsurance of program trigger
Program Trigger Coinsurance
Program Trigger Coinsurance
Letter of credit and performance obligations
Letter Of Credit And Performance Obligation
Letter Of Credit And Performance Obligation
Hotel Tower Developer LLC [Member]
Hotel Tower Developer LLC [Member]
Hotel Tower Developer LLC [Member]
Lessee, Lease, Description [Line Items]
Lessee, Lease, Description [Line Items]
Rental Revenue: Office
Rental Revenue Office
Rental Revenue Office
Earthquake Deductible Insurance Percentage of Value of the Affected Property Seattle
Earthquake Deductible Insurance Percentage of Value of the Affected Property Seattle
Earthquake Deductible Insurance Percentage of Value of the Affected Property Seattle
Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture
Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture
Unsecured exchangeable senior notes, net
Convertible Debt
Deductible in insurance as a percentage of the value of the affected property, San Francisco and Los Angeles
Earthquake Deductible Insurance Percentage Of Value Of The Affected Property San Francisco and Los Angeles
Earthquake Deductible Insurance Percentage Of Value Of The Affected Property San Francisco and Los Angeles
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax
Entity Shell Company
Entity Shell Company
Consolidation Items [Domain]
Consolidation Items [Domain]
Mortgages [Member]
Mortgages [Member]
Stockholders Equity / Partners Capital [Abstract]
Stockholders Equity / Partners Capital [Abstract]
Stockholders Equity / Partners Capital [Abstract]
Earnings Per Share / Common Unit
Earnings Per Share [Text Block]
Earnings Per Share [Abstract]
Earnings Per Share [Abstract]
Document Fiscal Period Focus
Document Fiscal Period Focus
Deferred Bonus and Profit Sharing Arrangements, Individual Contracts, Type of Deferred Compensation [Axis]
Deferred Bonus and Profit Sharing Arrangements, Individual Contracts, Type of Deferred Compensation [Axis]
Peer Group Issuers, Footnote
Peer Group Issuers, Footnote [Text Block]
Total liabilities
Liabilities
Trading Symbol
Trading Symbol
Schedule of Interest Rate Derivatives
Schedule of Interest Rate Derivatives [Table Text Block]
Company Selected Measure Name
Company Selected Measure Name
Derivative, Fixed Interest Rate
Derivative, Fixed Interest Rate
AVRS [Member]
AVRS [Member]
AVRS
Diluted earnings per common share / unit attributable to the Company
Diluted Earnings:
Earnings Per Share, Diluted [Abstract]
Vested 2012 OPP units and MYLTIPS
Conversion of 2012 OPP units and MYLTIPS [Member]
Conversion of 2012 OPP units and MYLTIPS
Depreciation and amortization
Depreciation and amortization expense
Depreciation, Depletion and Amortization, Nonproduction
Cash flows from operating activities:
Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract]
Entity Listing, Par Value Per Share
Entity Listing, Par Value Per Share
Dividends, Per Unit, Cash Paid
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid
Common Stock, Dividends, Per Share, Cash Paid
Equity Valuation Assumption Difference, Footnote
Equity Valuation Assumption Difference, Footnote [Text Block]
Line of Credit Facility [Table]
Line of Credit Facility [Table]
Amortization of interest rate contracts
Other Comprehensive Income, Other, Net of Tax
Dividends declared
Dividends
360 Park Avenue South Partners Entity
Three Six Zero Park Avenue South Partners Entity One [Member]
Three Six Zero Park Avenue South Partners Entity One
Dividends and distributions payable
Dividends and distributions declared but not paid
Dividends Payable
Entities [Table]
Entities [Table]
Tenant improvements
Leasehold Improvements, Gross
Disposal Groups, Including Discontinued Operations
Disposal Groups, Including Discontinued Operations [Table Text Block]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]
Company's share of net operating income from joint ventures
Net Operating Income
Gross Profit
Deferred Charges
Deferred Charges, Policy [Policy Text Block]
Cash Held in Escrows
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]
Proceeds from Issuance of Commercial Paper
Proceeds from Issuance of Commercial Paper
Amount of earthquake insurance provided by IXP, LLC as direct insurer San Francisco and Los Angeles
Amount Of Earthquake Insurance Provided By IXP LLC As Direct Insurer San Francisco and Los Angeles
Amount Of Earthquake Insurance Provided By IXP LLC As Direct Insurer San Francisco and Los Angeles
Lease liabilities - operating leases
Increase (Decrease) in Other Operating Assets and Liabilities, Net
Long-Lived Asset, Held-for-Sale
Long-Lived Asset, Held-for-Sale [Table Text Block]
Investments In Unconsolidated Joint Ventures [Abstract]
Investments In Unconsolidated Joint Ventures [Abstract]
Investments In Unconsolidated Joint Ventures [Abstract]
Award Timing Predetermined
Award Timing Predetermined [Flag]
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Property and Terrorism
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Property and Terrorism
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Property and Terrorism
MYLTIP 2025
MYLTIP Two Thousand Twenty Five [Member]
MYLTIP Two Thousand Twenty Five
Adjustment To PEO Compensation, Footnote
Adjustment To PEO Compensation, Footnote [Text Block]
Fair Value, Inputs, Level 1
Fair Value, Inputs, Level 1 [Member]
Gains from investments in securities
Gain (Loss) on Sale of Investments
Program trigger deductible
Program trigger deductible
Program trigger deductible
Fair Value of Financial Instruments
Fair Value of Financial Instruments, Policy [Policy Text Block]
Stock Based Compensation (in shares / units)
Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements
The Lofts at Atlantic Wharf
The Lofts at Atlantic Wharf [Member]
The Lofts at Atlantic Wharf
ATM Program [Member]
Atm Program [Member]
Prior Atm Program [Member]
Change in real estate included in accounts payable and accrued expenses
Change in real estate included in accounts payable and accrued expenses
The net change during the reporting period in future cash outflow to pay for purchases of fixed assets, construction in progress expenditures, deferred leasing costs and other investing activity costs that have occurred.
Salaries And Related Costs Capitalized
Salaries And Related Costs Capitalized
Salaries And Related Costs Capitalized
Excess stock, $0.01 par value, 150,000,000 shares authorized, none issued or outstanding
Excess Stock Value
Excess Stock Value
Preferred stock, par value
Preferred Stock, Par or Stated Value Per Share
Long-Term Debt, Fair Value
Long-Term Debt, Fair Value
Real Estate, Other [Member]
Real Estate, Other [Member]
Scenario [Domain]
Scenario [Domain]
751 Gateway Holdings LLC
751 Gateway Holdings LLC [Member]
751 Gateway Holdings LLC
Right of use assets - operating leases (amounts related to VIEs of $117,282 and $0 at September 30, 2026 and December 31, 2025, respectively)
Right of use assets - operating leases (amounts related to VIEs of $117,282 and $0 at September 30, 2026 and December 31, 2025, respectively)
Right of use assets - operating leases
Operating Lease, Right-of-Use Asset
Investments In Affiliates Subsidiaries Associates And Joint Ventures net
Investments In Affiliates Subsidiaries Associates And Joint Ventures net
Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.
Related party note receivable contributed in exchange for investment in unconsolidated joint venture
Related party note receivable contributed in exchange for investment in unconsolidated joint venture
Related party note receivable contributed in exchange for investment in unconsolidated joint venture
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Abstract]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Noncontrolling Interest [Line Items]
Noncontrolling Interest [Line Items]
Unsecured line of credit
Long-Term Line of Credit
Expiration Date
Trading Arrangement Expiration Date
Sales-type lease receivable, net
Sales-Type Lease, Net Investment in Lease, after Allowance for Credit Loss, Current
Cumulative Effect, Period of Adoption, Adjustment
Cumulative Effect, Period of Adoption, Adjustment [Member]
Total equity / capital
Equity, value
Equity, value
Equity, Including Portion Attributable to Noncontrolling Interest
Subordinated Debt
Subordinated Debt [Member]
Nonrelated Party
Nonrelated Party [Member]
Affiliated Entity
Affiliated Entity [Member]
Loss Contingency, Estimate of Possible Loss
Loss Contingency, Estimate of Possible Loss
Aggregate Pension Adjustments Service Cost
Aggregate Pension Adjustments Service Cost [Member]
Derivative [Table]
Derivative [Table]
Other income (expense)
Other Income and Expenses [Abstract]
Boston [Member]
Boston [Member]
Boston [Member]
Number of Units in Real Estate Property
Number of Units in Real Estate Property
Rental Expenses: Residential
Rental Expenses Residential
Rental Expenses Residential.
Commercial Real Estate Properties [Member]
Commercial Real Estate [Member]
Estimated liability, not accrued
Estimated liability, not accrued
Estimated liability, not accrued
Cash flows from investing activities:
Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract]
Entity Voluntary Filers
Entity Voluntary Filers
Related Party Transaction [Axis]
Related Party Transaction [Axis]
Unrecognized compensation expenses
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount
Document Financial Statement Error Correction [Flag]
Document Financial Statement Error Correction [Flag]
Interest Rate Swap
Interest Rate Swap [Member]
Noncontrolling interest - common units of the Operating Partnership
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable
Debt Disclosure [Text Block]
Debt Disclosure [Text Block]
Scenario [Axis]
Scenario [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]
Disposal Group Classification [Domain]
Disposal Group Classification [Domain]
Related party note receivable, net
Financing Receivable, after Allowance for Credit Loss
Debt Issuance Costs, Net
Debt Issuance Costs, Net
PEO Actually Paid Compensation Amount
PEO Actually Paid Compensation Amount
Total expenses
Costs and Expenses
Capital contributions to unconsolidated joint ventures
Payments to Acquire Equity Method Investments
Payments to Acquire Equity Method Investments
Debt Instrument, Interest Rate, Stated Percentage
Debt Instrument, Interest Rate, Stated Percentage
Text Block [Abstract]
Total stockholders' equity attributable to BXP, Inc.
Members’/Partners’ equity
Equity, Attributable to Parent
Real Estate [Domain]
Real Estate [Domain]
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]
7750 Wisconsin Avenue LLC [Member]
Seven seven five zero Wisconsin Avenue LLC [Member]
7750 Wisconsin Avenue LLC [Member]
ASSETS
Assets [Abstract]
MYLTIP 2023
MYLTIP Two Thousand Twenty Three [Member]
MYLTIP Two Thousand Twenty Three
Shady Grove Parcel One
Shady Grove Parcel One [Member]
Shady Grove Parcel One
Other Investments
Other Investments
Insider Trading Policies and Procedures [Line Items]
Derivative, Cap Interest Rate
Derivative, Cap Interest Rate
Noncontrolling interests in property partnerships
Partners' Capital Attributable to Noncontrolling Interest
Los Angeles [Member]
Los Angeles [Member]
Los Angeles [Member]
Capped call transactions premium
Payments for Derivative Instrument, Financing Activities
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Cash FDIC Insured Limit
Cash FDIC Insured Limit
Cash FDIC Insured Limit
Entity Central Index Key
Entity Central Index Key
Equity [Abstract]
Equity [Abstract]
Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year
Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member]
Payments for Legal Settlements
Payments for Legal Settlements
Safeco Partner Entity One [Member]
Safeco Partner Entity One [Member]
Safeco Partner Entity One
Other comprehensive (income) loss attributable to noncontrolling interest
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest
Contractual Sale Price
Contractual Sale Price
Contractual Sale Price
Liabilities held for sale
Disposal Group, Including Discontinued Operation, Liabilities
Long-Lived Asset, Held-for-Sale [Table]
Long-Lived Asset, Held-for-Sale [Table]
Ownership [Axis]
Ownership [Axis]
Fair Value Hierarchy and NAV [Axis]
Fair Value Hierarchy and NAV [Axis]
3-Month United States Treasury Bills
Cash Equivalent, US Government Security, Carrying Value
Investment, Name [Axis]
Investment, Name [Axis]
Conversion of redeemable partnership units, value
Partners' Capital Account, Exchanges and Conversions
Gateway Commons and 7750 Wisconsin Avenue
Gateway Commons and Seven Seven Five Zero Wisconsin Avenue [Member]
Gateway Commons and Seven Seven Five Zero Wisconsin Avenue
3 Hudson Boulevard [Member]
Three Hudson Boulevard [Member]
3 Hudson Boulevard [Member]
Debt Instrument, Basis Spread on Variable Rate
Debt Instrument, Basis Spread on Variable Rate
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)
Restricted Stock [Member]
Restricted Stock [Member]
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Attributable to Parent [Member]
All Individuals
All Individuals [Member]
Dividends and distributions
Payments of Dividends
Weighted-average period (years)
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition
Net Income 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 Loss Available To Common Stockholders After Allocation of Undistributed Earnings to Participating Securities Basic
Beach Cities Media Campus
Beach Cities Media Campus [Member]
Beach Cities Media Campus
Statement [Line Items]
Statement [Line Items]
Total assets
Assets
1265 Main Office JV LLC [Member]
One Two Six Five Main Office JV LLC [Member]
1265 Main Office JV LLC [Member]
Extended Maturity
Extended Maturity [Member]
Number of extensions
Number of extensions
Number of extensions
Convertible Debt
Convertible Debt [Member]
Total partners’ capital
Partners' Capital
Stock Option and Incentive Plan
Share-Based Payment Arrangement [Text Block]
1330 Connecticut Avenue
One Three Three Zero Connecticut Avenue [Member]
One Three Three Zero Connecticut Avenue
PEO
PEO [Member]
Equity Method Investment, Realized Gain (Loss) on Disposal
Equity Method Investment, Realized Gain (Loss) on Disposal [Table Text Block]
Equity Method Investment, Realized Gain (Loss) on Disposal
Issuance of restricted securities to employees and non-employee directors
Issuance of restricted securities to employees and directors
Issuance of restricted securities to employees and directors
Forgone Recovery due to Violation of Home Country Law, Amount
Forgone Recovery due to Violation of Home Country Law, Amount
Dividends In Excess Of Earnings [Member]
Dividends In Excess Of Earnings [Member]
Retained Earnings [Member]
Operating
Operating Expenses
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding
Equity, shares
Equity, shares
Common Stock, Shares, Outstanding
Award Timing Disclosures [Line Items]
Fair Value, by Balance Sheet Grouping [Table Text Block]
Fair Value, by Balance Sheet Grouping [Table Text Block]
Diluted Earnings: Net income (Loss), Per Share Amount (in dollars per share / unit)
Earnings Per Share, Diluted
Earnings Per Share, Diluted
Variable lease payments
Operating Lease, Variable Lease Income
Prepaid expenses and other assets
Increase (Decrease) in Prepaid Expense and Other Assets
Interest capitalized
Interest Costs Capitalized
Number of Leases
Number of Leases
Number of Leases
Unrealized gain (loss) on non-real estate investments
Unrealized Gain (Loss) on Investments
Wholly Owned Properties
Wholly Owned Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Table]
Consolidation, Less-than-Wholly-Owned Subsidiary, Parent Ownership Interest, Effect of Change [Table]
Ownership [Domain]
Ownership [Domain]
Net Assets Acquired
Business Combination, Recognized Asset Acquired, Asset
Basis differentials
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Payment Arrangement [Abstract]
Sales-type Lease, Lease Income
Sales-type Lease, Lease Income [Table Text Block]
Investments In Unconsolidated Joint Ventures
Equity Method Investments [Table Text Block]
Equity Awards Adjustments, Footnote
Equity Awards Adjustments, Footnote [Text Block]
Lessor, Leases
Lessor, Leases [Policy Text Block]
Accrued interest payable
Increase (Decrease) in Interest Payable, Net
Company's Taxable Income Distribution
Company's Taxable Income Distribution
Company's Taxable Income Distribution
Construction in Progress
Construction in Progress [Member]
Gross purchase price - development costs
Asset Acquisition, Consideration Transferred, Other Assets
Schedule of Equity Method Investments [Table]
Equity Method Investment [Table]
Operating partnership guarantee to cover liabilities of IXP
Operating partnership guarantee to cover liabilities of subsidiary
Operating partnership guarantee to cover liabilities of subsidiary
Equity Offering Costs
Equity Offering Costs Policy [Policy Text Block]
Equity Offering Costs Policy
Noncontrolling interest - property partnerships [Member]
Noncontrolling interest - property partnerships [Member]
Noncontrolling interest - property partnerships [Member]
Distribution Declared to OP, LTIP, OPP and MYLTIP Units [Table Text Block]
Dividends Declared [Table Text Block]
Dividends Declared [Table Text Block]
Delayed Draw Term Loan (DDTL)
Delayed Draw Term Loan (DDTL) [Member]
Finance Lease, Liability, Maturity
Finance Lease, Liability, to be Paid, Maturity [Table Text Block]
Long-term Debt, Maturity Date
Long-Term Debt, Maturity Date
Related Party Transaction [Domain]
Related Party Transaction [Domain]
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]
Entity Owning Land And Infrastructure Of Project [Member]
Entity Owning Land And Infrastructure Of Project [Member]
Entity Owning Land And Infrastructure Of Project [Member]
Summary Of Significant Accounting Policies [Table]
Summary Of Significant Accounting Policies [Table]
Summary Of Significant Accounting Policies [Table]
Rule 10b5-1 Arrangement Adopted
Rule 10b5-1 Arrangement Adopted [Flag]
Debt Instrument, Collateral
Debt Instrument, Collateral
Land, Buildings and Improvements
Land, Buildings and Improvements [Member]
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
Impairment Losses
Asset, Impairment Loss
OP unit conversion rate (in shares)
OP Unit Conversion Rate
OP Unit Conversion Rate.
Common stock, shares issued
Common Stock, Shares, Issued
Entity Information [Line Items]
Entity Information [Line Items]
Amount of gain (loss) related to the ineffective portion and amount excluded from effectiveness testing
Gain (Loss) from Components Excluded from Assessment of Cash Flow Hedge Effectiveness, Net
Tenant and other receivables, net
Increase (Decrease) in Accounts Receivable
Deferred charges, net (amounts related to VIEs of $253,548 and $204,924 at September 30, 2026 and December 31, 2025, respectively)
Deferred Costs, Noncurrent
Product and Service [Domain]
Product and Service [Domain]
Class of Stock [Line Items]
Class of Stock [Line Items]
290 Binney Street
Two Nine Zero Binney [Member]
290 Binney
Compensation Actually Paid vs. Other Measure
Compensation Actually Paid vs. Other Measure [Text Block]
Limited Partner [Member]
Limited Partner [Member]
Impaired Long-Lived Assets Held and Used, Asset Name [Domain]
Impaired Long-Lived Assets Held and Used, Asset Name [Domain]
360 PAS Holdco LLC (indirect ownership)
Three Six Zero PAS Holdco LLC (indirect ownership) [Member]
Three Six Zero PAS Holdco LLC (indirect ownership)
Per occurrence limit for NBCR Coverage
Per occurrence limit for NBCR Coverage
Per occurrence limit for NBCR Coverage
Termination Date
Trading Arrangement Termination Date
Noncontrolling Interest [Table]
Noncontrolling Interest [Table]
Subsequent Events [Abstract]
Subsequent Events [Abstract]
In-place lease intangibles
Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Finite-Lived
Compensation Actually Paid vs. Total Shareholder Return
Compensation Actually Paid vs. Total Shareholder Return [Text Block]
Investments in securities
Marketable Securities
Entity Public Float
Entity Public Float
Fair Value as of Grant Date
Award Grant Date Fair Value
Pay vs Performance Disclosure, Table
Pay vs Performance [Table Text Block]
Management Service [Member]
Management Service [Member]
Arrangement Duration
Trading Arrangement Duration
Metropolitan Square
Metropolitan Square [Member]
Metropolitan Square
Retail Site [Member]
Retail Site [Member]
Consolidation Items [Axis]
Consolidation Items [Axis]
Entity Address, Postal Zip Code
Entity Address, Postal Zip Code
Entity Registrant Name
Entity Registrant Name
Construction in progress
Payments to Acquire Other Productive Assets
Insider Trading Policies and Procedures Not Adopted
Insider Trading Policies and Procedures Not Adopted [Text Block]
Total revenue
Total revenue
Revenues
Gain on sale / consolidation
Equity Method Investment, Realized Gain (Loss) on Disposal
Income (loss) from unconsolidated joint ventures
Income (loss) from unconsolidated joint ventures
Income (loss) from unconsolidated joint ventures
Income (Loss) from Equity Method Investments
Income (Loss) from Equity Method Investments
Construction in progress from prepaid expenses and other assets
Construction in progress from prepaid expenses and other assets
Construction in progress from prepaid expenses and other assets
Accounts payable and accrued expenses
Increase (Decrease) in Accounts Payable and Accrued Liabilities
Forgone Recovery due to Expense of Enforcement, Amount
Forgone Recovery due to Expense of Enforcement, Amount
Ltips (including vested MYLTIPS) And Restricted Stock [Member]
Ltips (including vested MYLTIPS) And Restricted Stock [Member]
LTIPs (including vested MYLTIPS) and Restricted Stock [Member].
Gateway Commons Complex [Member]
Gateway Commons Complex [Member]
Gateway Commons Complex [Member]
Rosecrans-Sepulveda Partners 4, LLC
Rosecrans-Sepulveda Partners Four, LLC [Member]
Rosecrans-Sepulveda Partners Four, LLC
Loan Restructuring Modification [Axis]
Loan Restructuring Modification [Axis]
3.495% unsecured senior notes
Three point four nine five percent unsecured senior notes [Member]
3.495% unsecured senior notes
Impairment losses
Impairment losses
Impairment of Real Estate
Vesting Period
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period
Intangible Asset, Finite-Lived, Class [Domain]
Intangible Asset, Finite-Lived, Class [Domain]
Award Type [Domain]
Award Type [Domain]
Fair Value, Inputs, Level 3
Fair Value, Inputs, Level 3 [Member]
7750 Wisconsin Avenue [Member]
Seven Seven Five Zero Wisconsin Avenue [Member]
7750 Wisconsin Avenue [Member]
Gain on Unconsolidated Joint Venture Investment
Gain on Unconsolidated Joint Venture Investment
Gain on Unconsolidated Joint Venture Investment
Sales-type lease revenue
Sales-type Lease, Revenue
2027
Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year One
Closing price of common stock (in dollars per share)
Share Price
Subsidiary, Ownership Percentage, Noncontrolling Owner
Subsidiary, Ownership Percentage, Noncontrolling Owner
Geographical [Axis]
Geographical [Axis]
Schedule Of Aggregate Principal Payments On Mortgage Notes
bxp_ScheduleOfAggregatePrincipalPaymentsOnMortgageNotesTableTextBlock [Table Text Block]
bxp_ScheduleOfAggregatePrincipalPaymentsOnMortgageNotesTableTextBlock
Other assets
Other Assets
Finance Lease, Liability, Reversal from Re-Assessment
Finance Lease, Liability, Reversal from Re-Assessment
Finance Lease, Liability, Reversal from Re-Assessment
Legal Entity [Axis]
Legal Entity [Axis]
Company's share of equity
Company Share Of Equity
Company Share Of Equity
Non-cash contributions from noncontrolling interests in property partnerships, net
Non-cash contributions from noncontrolling interests in property partnerships, net
Non-cash contributions from noncontrolling interests in property partnerships, net
Lessee, Lease, Description [Table]
Lessee, Lease, Description [Table]
Investments in Joint Ventures
Equity Method Investments [Policy Text Block]
Cash and cash equivalents and cash held in escrows, beginning of period
Cash and cash equivalents and cash held in escrows, end of period
Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation
BNY Tower Holdings LLC [Member]
Dock 72
BNY Tower Holdings LLC [Member]
BNY Tower Holdings LLC [Member]
Non-NEOs
Non-NEOs [Member]
Ownership Percentage
Equity Method Investment, Ownership Percentage
Land
Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment, Land
2028
Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Two
3.505% unsecured senior notes
Three point five zero five percent unsecured senior notes [Member]
3.505% unsecured senior notes
Investment, Name [Domain]
Investment, Name [Domain]
Lessee, Operating Leases
Lessee, Operating Leases [Text Block]
Long-term Debt, Type [Domain]
Long-Term Debt, Type [Domain]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]
Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block]
Range [Axis]
Statistical Measurement [Axis]
Derivative Instruments, Gain (Loss)
Derivative Instruments, Gain (Loss) [Table Text Block]
Award Type [Axis]
Award Type [Axis]
Lessor Disclosure [Abstract]
Lessor Disclosure [Abstract]
Named Executive Officers, Footnote
Named Executive Officers, Footnote [Text Block]
Noncontrolling interest - Redeemable partnership units [Member]
Noncontrolling interest - Redeemable partnership units [Member]
Noncontrolling interest - Redeemable partnership units [Member]
Dividends in excess of earnings
Retained Earnings (Accumulated Deficit)
Repayments of Commercial Paper
Repayments of Commercial Paper
Product and Service [Axis]
Product and Service [Axis]
Real Estate
Real Estate, Policy [Policy Text Block]
Awards Close in Time to MNPI Disclosures
Awards Close in Time to MNPI Disclosures [Table]
Washington, DC [Member]
DISTRICT OF COLUMBIA
Common Stock [Member]
Common Stock [Member]
Operating Lease, Lease Income [Table Text Block]
Operating Lease, Lease Income [Table Text Block]
Earnings Per Share Reconciliation Disclosure
Earnings Per Share Reconciliation Disclosure
Number of shares issued
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period
Long-Lived Assets Held-for-Sale, Name [Domain]
Long-Lived Assets Held-for-Sale, Name [Domain]
Stockholders Equity / Partner Capital [Abstract]
Stockholders Equity / Partner Capital [Abstract]
Stockholders Equity / Partner Capital [Abstract]
Noncontrolling Interest [Abstract]
Noncontrolling Interest [Abstract]
Straight Line Rent Adjustments
Straight Line Rent Adjustments
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]
Derivative Contract [Domain]
Derivative Contract [Domain]
Tenant and Other Receivables and Notes Receivable
Receivable [Policy Text Block]
Accounting Standards Update [Domain]
Accounting Standards Update [Domain]
Real Estate Properties [Axis]
Real Estate Property Ownership [Axis]
Unrealized gain (loss) on non-real estate investments
Other Nonoperating Gains (Losses)
Total liabilities and equity / capital
Liabilities and Equity
Employee Stock Option
Share-Based Payment Arrangement, Option [Member]
Additional 402(v) Disclosure
Additional 402(v) Disclosure [Text Block]
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value
2.984% unsecured senior notes
Two point nine eight four percent unsecured senior notes [Member]
2.984% unsecured senior notes
Related Party [Domain]
Related and Nonrelated Parties [Domain]
Tabular List, Table
Tabular List [Table Text Block]
Exchangeable Debt, Policy
Exchangeable Debt, Policy [Policy Text Block]
Exchangeable Debt, Policy
Additional paid-in capital
Additional Paid in Capital
Net Rentable Area (in sf)
Net Rentable Area
2029
Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Three
Period from August 20, 2026 through December 31, 2026
Intangible Asset, Finite-Lived, Estimated Amortization Expense, Remainder of Fiscal Year
Name
Awards Close in Time to MNPI Disclosures, Individual Name
Real Estate Properties [Line Items]
Real Estate Properties [Line Items]
Real Estate Investment Trust, Distribution, Tax Status
Real Estate Investment Trust, Distribution, Tax Status [Table Text Block]
Real Estate Investment Trust, Distribution, Tax Status
Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested
Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member]
Net (income) loss attributable to noncontrolling interests
Net Income (Loss) Attributable to Noncontrolling Interest [Abstract]
Property, Plant and Equipment, Type [Domain]
Long-Lived Asset, Class [Domain]
Difference Between Proceeds from Sale and Noncontrolling Interest
Difference Between Proceeds from Sale and Noncontrolling Interest
Difference Between Proceeds from Sale and Noncontrolling Interest
Property, Plant, and Equipment [Table]
Property, Plant, and Equipment [Table]
Preferred stock, $0.01 par value, 50,000,000 shares authorized, none issued or outstanding
Preferred Stock, Value, Issued
CA-Colorado Center LLC[Member]
Colorado Center
CA-Colorado Center LLC [Member]
CA-Colorado Center LLC [Member]
Adjustment to Compensation:
Adjustment to Compensation [Axis]
North First Business Park
North First Business Park [Member]
North First Business Park
Derivative, Average Fixed Interest Rate
Derivative, Average Fixed Interest Rate
Dividends Payable [Line Items]
Dividends / Distributions [Line Items]
Dividends Payable [Line Items]
Dividends Payable [Table]
Dividends Payable [Table]
Sales-type and Direct Financing Leases, Lease Receivable, Maturity
Sales-Type and Direct Financing Leases, Payment to be Received, Maturity [Table Text Block]
Safeco Plaza
Safeco Plaza [Member]
Safeco Plaza
Rule 10b5-1 Arrangement Terminated
Rule 10b5-1 Arrangement Terminated [Flag]
Aggregate Erroneous Compensation Amount
Aggregate Erroneous Compensation Amount
Cash paid for interest (net of amounts capitalized)
Interest Paid, Excluding Capitalized Interest, Operating Activity
Parking and Other [Member]
Parking and Other [Member]
Parking and Other [Member]
Sum of Coverage Covered by IXP and Excess Coverage for Property and Terrorism
Sum of Coverage Covered by IXP and Excess Coverage for Property and Terrorism
Sum of Coverage Covered by IXP and Excess Coverage for Property and Terrorism
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award
Share-Based Compensation Arrangement by Share-Based Payment Award, Terms of Award
Total
Assets, Fair Value Disclosure
Name
Measure Name
Pay vs Performance Disclosure [Line Items]
Fair Value Hierarchy and NAV [Domain]
Fair Value Hierarchy and NAV [Domain]
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Entity Information, Former Legal or Registered Name
Entity Information, Former Legal or Registered Name
Additional Paid-In Capital [Member]
Additional Paid-in Capital [Member]
Rental Revenue: Residential
Rental Revenue Residential
Rental Revenue Residential.
Accrued Liabilities
Accrued Liabilities
Name
Trading Arrangement, Individual Name
Number of extension options
Number of extension options
Number of extension options
Cash and cash equivalents (amounts related to VIEs of $280,171 and $255,631 at September 30, 2026 and December 31, 2025, respectively)
Cash and cash equivalents, beginning of period
Cash and cash equivalents, end of period
Cash and Cash Equivalent
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
Capitalized amortization of deferred financing costs
Capitalized amortization of deferred financing costs
Capitalized amortization of deferred financing costs
Company Selected Measure Amount
Company Selected Measure Amount
Schedule Of Reconciliation Of Net Operating Income To Net Income
Segment Reporting, Reconciliation of Profit (Loss) by Segment to Consolidated [Table Text Block]
Unearned compensation
Partners' Capital Account, Deferred Compensation
Depreciation and amortization
Depreciation, Depletion and Amortization
Land held for future development
Land Available for Development
Net activity from contributions and unearned compensation
Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture
Extension Option (in years)
Extension Option (in years)
Extension Option (in years)
Real Estate [Abstract]
Real Estate [Abstract]
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability
Non-PEO NEO
Non-PEO NEO [Member]
Losses from interest rate contracts
Gain (Loss) on Fair Value Hedges Recognized in Earnings
Number of VIEs
Number of VIEs
Number of VIEs
Operating expense
Operating expense
Operating expense
Cost of Product and Service Sold
Award Timing Method
Award Timing Method [Text Block]
Net increase (decrease) in cash and cash equivalents and cash held in escrows
Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation
Amount of gain (loss) related to the effective portion subsequently reclassified to earnings (2)
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net
Forecast
Forecast [Member]
Forgone Recovery, Explanation of Impracticability
Forgone Recovery, Explanation of Impracticability [Text Block]
Other Unconsolidated JVS
Other Unconsolidated JVS [Member]
Other Unconsolidated JVS
Net Income (Loss) Attributable to the Company
Net Income (Loss) Attributable to Parent
Long-term Debt, Type [Axis]
Long-Term Debt, Type [Axis]
Erroneous Compensation Analysis
Erroneous Compensation Analysis [Text Block]
ABXP Worldgate Investments LLC
ABXP Worldgate Investments LLC [Member]
ABXP Worldgate Investments LLC
Change in Accounting Principle, Accounting Standards Update, Adoption Date
Change in Accounting Principle, Accounting Standards Update, Adoption Date
Restatement Determination Date:
Restatement Determination Date [Axis]
Excess stock, shares authorized
Excess Stock, Shares Authorized
Lessee, Leases
Lessee, Leases [Policy Text Block]
Fixed Rate Mortgage [Member]
Fixed Rate Mortgage [Member]
Fixed Rate Mortgage
REIT Distribution Requirement
REIT Distribution Requirement
REIT Distribution Requirement
LTIP and 2026 MYLTIP Units [Member]
LTIP and 2026 MYLTIP Units [Member]
LTIP and 2026 MYLTIP Units [Member].
Revenue
Revenues [Abstract]
Company's Share of Net Operating Income: % of Grand Totals
Percentage of Company's Share of Net Operating Income
Percentage of Company's Share of Net Operating Income
Noncontrolling interest:
Temporary Equity [Abstract]
Pension Benefits Adjustments, Footnote
Pension Benefits Adjustments, Footnote [Text Block]
Investment in unconsolidated joint ventures funded by related party note receivable contributed
Investment in unconsolidated joint ventures funded by related party note receivable contributed
Investment in unconsolidated joint ventures funded by related party note receivable contributed
Environmental Focused Investment Fund
Environmental Focused Investment Fund [Member]
Environmental Focused Investment Fund
Asset Acquisition [Table]
Asset Acquisition [Table]
Range [Domain]
Statistical Measurement [Domain]
Impaired Long-Lived Assets Held and Used by Type [Axis]
Impaired Long-Lived Assets Held and Used by Type [Axis]
Document Fiscal Year Focus
Document Fiscal Year Focus
Loss on sales-type lease
Loss on sales-type lease
Gain on sales type lease
Sales-type and Direct Financing Leases, Profit (Loss)
Safeco Plaza REIT LLC
Safeco Plaza REIT LLC [Member]
Safeco Plaza REIT LLC
LTIP Units [Member]
LTIP Units [Member]
LTIP Units [Member].
Beginning Balance
Partners' Capital, Including Portion Attributable to Noncontrolling Interest
Unrealized (gain) loss on non-real estate investments
Nonoperating Gains (Losses)
Remaining Other Investment
Remaining Other Investment [Member]
Remaining Other Investment
Accrued rental income, net (amounts related to VIEs of $484,313 and $470,734 at September 30, 2026 and December 31, 2025, respectively)
Deferred Rent Receivables, Net
Shared-based Compensation Arrangement by Share-based Payment Award, Performance requirement
Shared-based Compensation Arrangement by Share-based Payment Award, Performance requirement [Table Text Block]
Shared-based Compensation Arrangement by Share-based Payment Award, Performance-based Vesting Requirement
Rental
Direct Costs of Leased and Rented Property or Equipment
Common stock, $0.01 par value, 250,000,000 shares authorized, 159,751,217 and 158,627,198 issued and 159,672,317 and 158,548,298 outstanding at September 30, 2026 and December 31, 2025, respectively
Common Stock, Value, Issued
Interest expense
Interest expense
Interest Expense, Operating and Nonoperating
Schedule of Long-term Debt Instruments
Schedule of Long-Term Debt Instruments [Table Text Block]
Line of Credit [Member]
Line of Credit [Member]
Restatement Determination Date
Restatement Determination Date
Investments in unconsolidated joint ventures
Carying value of the Company's investment in unconsolidated joint ventures
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
CAB 290 Coles Venture LLC
CAB 290 Coles Venture LLC [Member]
CAB 290 Coles Venture LLC
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic
Allocation of undistributed earnings to participating securities
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic
Stock Based Compensation
Dilutive Securities, Effect on Basic Earnings Per Share
Leases, Acquired-in-Place
Leases, Acquired-in-Place [Member]
Amendment Flag
Amendment Flag
Proceeds from sales of investments in unconsolidated joint ventures
Proceeds from Sale of Equity Method Investments
New York [Member]
NEW YORK
Payments on finance lease obligations
Finance Lease, Principal Payments
Less: accumulated depreciation (amounts related to VIEs of $(1,877,361) and $(1,763,988) at September 30, 2026 and December 31, 2025, respectively)
Less: accumulated depreciation
Real Estate Investment Property, Accumulated Depreciation
Disposal Group Classification [Axis]
Disposal Group Classification [Axis]
Internal Rate of return on preferred equity
Internal Rate of return on preferred equity
Internal Rate of return on preferred equity
Loss Contingency, Number of Defendants
Loss Contingency, Number of Defendants
Building and improvements
Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment, Building
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2026 and December 31, 2025, respectively)
Finance Lease, Right-of-Use Asset, before Accumulated Amortization
Investments [Domain]
Investments [Domain]
Disposal Group, Held-for-Sale, Not Discontinued Operations
Disposal Group, Held-for-Sale, Not Discontinued Operations [Member]
Debt Instrument, Maturity Date
Debt Instrument, Maturity Date
Adjustment to Non-PEO NEO Compensation Footnote
Adjustment to Non-PEO NEO Compensation Footnote [Text Block]
Entity Address, State or Province
Entity Address, State or Province
PEO Total Compensation Amount
PEO Total Compensation Amount
Derivative, Notional Amount
Derivative, Notional Amount
Investment in unconsolidated joint ventures funded by real estate contributed
Investment in unconsolidated joint ventures funded by real estate contributed
Investment in unconsolidated joint ventures funded by real estate contributed
Weighted average number of common shares / units outstanding (in shares / units)
Net income (loss) attributable to the company (in shares / units)
Weighted Average Number of Shares Outstanding, Basic
Net activity from stock option and incentive plan
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)
Reservoir Place
Reservoir Place [Member]
Reservoir Place
Boston Properties Limited Partnership
Partners' Capital (General and Limited Partners)[Member]
Boston Properties Limited Partnership [Member]
Boston Properties Limited Partnership
2.671% unsecured senior notes
Two point six seven one percent unsecured senior notes [Member]
Two point six seven one percent unsecured senior notes
Mortgage notes payable, net (amounts related to VIEs of $3,318,571 and $3,286,870 at September 30, 2026 and December 31, 2025, respectively)
Mortgage notes payable, net
Mortgage and notes payable, net
Secured Debt
Fair Value, by Balance Sheet Grouping [Table]
Fair Value, by Balance Sheet Grouping [Table]
Consolidated Properties
Consolidated Properties [Member]
Real estate and intangibles recorded upon consolidation
Transfer to Investments
Loss Contingency, Portion Not Accrued
Loss Contingency, Range of Possible Loss, Portion Not Accrued
Acquisition of noncontrolling interest in property partnership
Payments to Acquire Additional Interest in Subsidiaries
Company's share of net income (loss)
Companys share of net income (loss)
Company's share of net income (loss)
Interest and other income
Interest and Other Income
Interest and Other Income
Other revenue
Revenue from Contract with Customer, Including Assessed Tax
Rental Expenses: Office
Rental Expenses Office
Rental Expenses Office
Gross purchase price
Asset Acquisition, Consideration Transferred
ICFR Auditor Attestation Flag
ICFR Auditor Attestation Flag
Unsecured commercial paper
Commercial Paper
Treasury Stock
Treasury Stock [Policy Text Block]
Treasury Stock
Entity Information [Line Items]
Document Information [Line Items]
Assets held for sale
Disposal Group, Including Discontinued Operation, Assets
Award Timing MNPI Disclosure
Award Timing MNPI Disclosure [Text Block]
Class of Stock [Axis]
Class of Stock [Axis]
Basis of Presentation
Basis of Accounting, Policy [Policy Text Block]
Adjustment to reflect redeemable partnership units at redemption value
Partners' Capital Account, Redemptions
Net Income (Loss) Attributable to the Company
Net Income (Loss) Available to Common Stockholders, Basic
Net Income (Loss) Available to Common Stockholders, Basic
Receivable [Domain]
Receivable [Domain]
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
Boston Properties Limited Partnership partners’ capital— 1,774,975 and 1,768,004 general partner units and 157,897,342 and 156,780,294 limited partner units outstanding at September 30, 2026 and December 31, 2025, respectively
General And Limited Partners Capital Account
General And Limited Partners Capital Account
Line of Credit Facility, Maximum Borrowing Capacity
Line of Credit Facility, Maximum Borrowing Capacity
601 Lexington Avenue
Six Zero One Lexington Avenue [Member]
Six Zero One Lexington Avenue [Member]
Accrued rental income, net
Straight Line Rent
Dock 72 [Member]
Dock Seven Two [Member]
Dock Seven Two
Realized Gain Loss On Sale of Real Estate
Realized Gain Loss On Sale of Real Estate [Table Text Block]
Realized Gain Loss On Sale of Real Estate
Treasury common stock at cost, 78,900 shares at September 30, 2026 and December 31, 2025
Treasury Stock, Value
New Accounting Pronouncements
New Accounting Pronouncements, Policy [Policy Text Block]
Earnings Per Share and Earnings Per Common Unit
Earnings Per Share, Policy [Policy Text Block]
Land
Land [Member]
Platform 16, 360 Park Avenue South, 200 Fifth Avenue and Safeco Plaza
Platform Sixteen, Three Six Zero Park Avenue South, Two Zero Zero Fifth Avenue and Safeco Plaza [Member]
Platform Sixteen, Three Six Zero Park Avenue South, Two Zero Zero Fifth Avenue and Safeco Plaza
Accounts Receivable, Collection Period Expected
Accounts Receivable, Collection Period Expected
Accounts Receivable, Collection Period Expected
Noncontrolling Interests [Member]
Noncontrolling Interest [Member]
751 Gateway Boulevard
Seven Five One Gateway Boulevard [Member]
Seven Five One Gateway Boulevard
Noncontrolling Interest Disclosure [Text Block]
Noncontrolling Interest Disclosure [Text Block]
Total
Long-Term Debt
Long-Term Debt
Debt Instrument, Offering Price Percentage
Debt Instrument, Offering Price Percentage
Debt Instrument, Offering Price Percentage
Change in assets and liabilities:
Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract]
Net cash used in investing activities
Cash Provided by (Used in) Investing Activity, Including Discontinued Operation
Equity Awards Adjustments, Excluding Value Reported in Compensation Table
Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member]
Stockholders' Equity / Partners' Capital
Equity [Text Block]
Expenses
Costs and Expenses [Abstract]
Security Exchange Name
Security Exchange Name
Reedemable deferred stock units, units
Temporary Equity, Shares Subscribed but Unissued
Fair Value Hedge Assets
Cash Flow Hedge Derivative Instrument Assets at Fair Value
Lessee Disclosure [Abstract]
Lessee Disclosure [Abstract]
Note receivable, net
Financing Receivable, before Allowance for Credit Loss
Amortization of sales type lease
Amortization of sales type lease
Amortization of sales type lease
Equity Method Investment, Other-than-Temporary Impairment
Impairment Loss on Investment
Equity Method Investment, Other-than-Temporary Impairment
Land, Residential, Retail and Office [Member]
Land, Residential, Retail and Office [Member]
Land, Residential, Retail and Office
Common stock available for issuance
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized
Right-of-use assets - finance leases
Finance Lease, Right-of-Use Asset, after Accumulated Amortization
Property, Plant, and Equipment
Property, Plant, and Equipment [Table Text Block]
Statement of Comprehensive Income [Abstract]
Statement of Comprehensive Income [Abstract]
Name
Outstanding Recovery, Individual Name
Award Timing, How MNPI Considered
Award Timing, How MNPI Considered [Text Block]
Total
Real Estate Investment Property At Cost Including Right of Use Assets
Real Estate Investment Property At Cost Including Right of Use Assets
Schedule of Share-Based Compensation, Employee Stock Purchase Plan, Activity
Schedule of Share-Based Compensation, Employee Stock Purchase Plan, Activity [Table Text Block]
Consolidation, Variable Interest Entity, Policy
Consolidation, Variable Interest Entity, Policy [Policy Text Block]
Geographical [Domain]
Geographical [Domain]
Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year
Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member]
Pension Adjustments Prior Service Cost
Pension Adjustments Prior Service Cost [Member]
BP-M 3HB Venture LLC
BP-M 3HB Venture LLC [Member]
BP-M 3HB Venture LLC
Effect of Dilutive Securities:
Weighted Average Number of Shares Outstanding, Diluted, Adjustment [Abstract]
Kingstowne Retail
Kingstowne Retail [Member]
Kingstowne Retail
Unrealized loss on derivative instruments
Unrealized Gain (Loss) on Derivatives
Subsidiary, Ownership Percentage, Parent
Subsidiary, Ownership Percentage, Parent
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships
Proceeds from Noncontrolling Interest, Cash Portion
Proceeds from Noncontrolling Interest, Cash Portion
Leased percentage
Leased percentage
Leased percentage
Debt
Long-Term Debt, Gross
Office Venture LLC
Office Venture LLC [Member]
Office Venture LLC
Value of MYLTIP Awards
Value of MYLTIP Awards
Value of MYLTIP Awards
Compensation Amount
Outstanding Recovery Compensation Amount
Individual:
Individual [Axis]
OP Units [Member]
Op Units [Member]
OP Units [Member]
Weighted average number of common and common equivalent shares / units outstanding (in shares / units)
Diluted Earnings: Net income (Loss) attributable to the Company (in shares / units)
Weighted Average Number of Shares Outstanding, Diluted
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)
Entity Emerging Growth Company
Entity Emerging Growth Company
Derivative Instruments and Hedging Activities
Derivatives, Policy [Policy Text Block]
2012 OPP and 2013-2023 MYLTIP [Member]
2012 OPP and 2013-2023 MYLTIP [Member]
2012 OPP and 2013-2023 MYLTIP
Underlying Security Market Price Change
Underlying Security Market Price Change, Percent
Borrowings on unsecured line of credit
Proceeds from Lines of Credit
Commercial Paper
Commercial Paper [Member]
Derivative Instruments and Hedging Activities Disclosure
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Rental Expenses: Total
Rental Expenses Operating Expenses Total
Rental Expenses Operating Expenses Total.
CAB 290 Coles Holdco LLC
CAB 290 Coles Holdco LLC [Member]
CAB 290 Coles Holdco LLC
Commitments And Contingencies [Line Items]
Commitments And Contingencies [Line Items]
Commitments And Contingencies [Line Items]
Number of Mezzanine Loan Receivables Held
Number of Mezzanine Loan Receivables Held
Number of Mezzanine Loan Receivables Held
Number Of Variable Mortgage Loans
Number Of Variable Mortgage Loans
Number Of Variable Mortgage Loans
Building, pre-development and other capital improvements
Payments for Capital Improvements
Treasury Stock, at cost [Member]
Treasury Stock, Common [Member]
Repayment/Redemption of unsecured senior notes
Repayments of Unsecured Debt
Furniture, Fixtures and Equipment
Furniture and Fixtures, Gross
Annual Aggregate Limit of Earthquake Insurance Seattle
Annual Aggregate Limit of Earthquake Insurance Seattle
Annual Aggregate Limit of Earthquake Insurance Seattle
Amount of gain (loss) related to the effective portion recognized in other comprehensive income (loss) (1)
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI
OP Units for redemption (in shares)
Stock Redeemed or Called During Period, Shares
Proceeds from unsecured senior notes
Proceeds from Issuance of Unsecured Debt
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Sumner Square
Sumner Square [Member]
Sumner Square
All Executive Categories
All Executive Categories [Member]
Interest rate swaps recorded upon consolidation
Interest rate swaps recorded upon consolidation
Interest rate swaps recorded upon consolidation
Employee and director payment per share (in dollars per share)
Employee and director payment per share
Employee and director payment per share
2024 Unsecured Term Loan
2024 Unsecured Term Loan [Member]
2024 Unsecured Term Loan
Pension Adjustments Service Cost
Pension Adjustments Service Cost [Member]
MYLTIP 2024
MYLTIP Two Thousand Twenty Four [Member]
MYLTIP Two Thousand Twenty Four
Redeemable deferred stock units— 123,995 and 111,701 units outstanding at redemption value at September 30, 2026 and December 31, 2025, respectively
Redeemable Noncontrolling Interest, Equity, Carrying Amount
Reconciliation of cash and cash equivalents and cash held in escrow
Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract]
Computation Of Basic And Diluted Earnings Per Share / Unit
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Debt Disclosure [Abstract]
Debt Disclosure [Abstract]
Segment Reporting [Text Block]
Segment Reporting [Text Block]
Minimum [Member]
Minimum [Member]
Investment Type [Axis]
Investment Type [Axis]
Repayment of unsecured term loan
Repayments of Other Debt
17 Hartwell Avenue JV LLC
Seventeen Hartwell JV LLC [Member]
Seventeen Hartwell JV LLC
Dividends
Dividend Policy [Policy Text Block]
Dividend Policy
Consolidated Entities, Ownership Percentage
Consolidated Entities, Ownership Percentage
Consolidated Entities, Ownership Percentage
Non-Real Estate Investments
Non-Real Estate Investments [Policy Text Block]
Non-Real Estate Investments
Liabilities:
Liabilities [Abstract]
Finite-lived Intangible Assets Amortization Expense
Intangible Asset, Finite-Lived, Amortization Expense [Table Text Block]
Income Statement Location [Axis]
Location, Statement of Income, Balance [Axis]
Worldgate Multifamily JV LLC
Worldgate Multifamily JV LLC [Member]
Worldgate Multifamily JV LLC
Borrowings on unsecured term loans
Proceeds from Other Debt
Investments in securities, net
Payments for (Proceeds from) Investments
Non-Rule 10b5-1 Arrangement Adopted
Non-Rule 10b5-1 Arrangement Adopted [Flag]
Limited Partners' Capital Account, Units Outstanding (in units)
Limited Partners' Capital Account, Units Outstanding
Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table
Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member]
Schedule of Real Estate Properties [Table]
Real Estate Property, Ownership [Table]
Other liabilities (amounts related to VIEs of $113,415 and $95,209 at September 30, 2026 and December 31, 2025, respectively)
Other Liabilities
Other Liabilities
Other Liabilities
2025 OPP
2025 OPP [Member]
2025 OPP
Residential Building
Apartment Building [Member]
Common stock, shares authorized
Common Stock, Shares Authorized
500 North Capitol Street, NW
Five Zero Zero North Capitol [Member]
Five Zero Zero North Capitol
Total real estate
Total real estate
Real Estate Investment Property, Net
Exercise Price
Award Exercise Price
San Francisco [Member]
San Francisco [Member]
San Francisco [Member]
Schedule of Equity Method Investments [Line Items]
Schedule of Equity Method Investments [Line Items]
Segment Reporting [Line Items]
Segment Reporting [Line Items]
Long-Lived Asset, Held-for-Sale [Line Items]
Long-Lived Asset, Held-for-Sale [Line Items]
860 and 870 Winter Street
Eight Six Zero and Eight Seven Zero Winter Street [Member]
Eight Six Zero and Eight Seven Zero Winter Street
Value of program trigger
Program Trigger Value
Program Trigger Value
Document Quarterly Report
Document Quarterly Report
Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested
Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member]
2.524% unsecured senior notes
Two point five two four percent unsecured senior notes [Member]
Two point five two four percent unsecured senior notes
Tenant and other receivables, net (amounts related to VIEs of $31,528 and $30,989 at September 30, 2026 and December 31, 2025, respectively)
Accounts Receivable, after Allowance for Credit Loss
Summary Of Significant Accounting Policies [Line Items]
Summary Of Significant Accounting Policies [Line Items]
Summary Of Significant Accounting Policies [Line Items]
Accrued interest payable
Interest Payable
Repayments of Long-Term Debt
Repayments of Long-Term Debt
Schedule of Noncontrolling Interest [Table Text Block]
Schedule of Noncontrolling Interest [Table Text Block]
Schedule of Noncontrolling Interest
Awards Close in Time to MNPI Disclosures, Table
Awards Close in Time to MNPI Disclosures [Table Text Block]
Real Estate
Real Estate Disclosure [Text Block]
Equity Component [Domain]
Equity Component [Domain]
Real Estate Properties [Domain]
Real Estate Properties [Domain]
Adoption Date
Trading Arrangement Adoption Date
Net activity from equity transactions
Proceeds from Issuance or Sale of Equity
Scenario, Plan
Scenario, Plan [Member]
Conversions of noncontrolling interests to stockholders’ equity
Conversions of noncontrolling interests to Stockholders' Equity
Conversions of noncontrolling interests to Stockholders' Equity
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
Per occurrence limit of the earthquake insurance which covers San Francisco and Los Angeles regions
Per Occurrence Limit Of Earth Quake Insurance San Francisco and Los Angeles
Per Occurrence Limit Of Earth Quake Insurance San Francisco and Los Angeles
Title
Trading Arrangement, Individual Title
Forgone Recovery due to Disqualification of Tax Benefits, Amount
Forgone Recovery due to Disqualification of Tax Benefits, Amount
Accounting Policies [Abstract]
Accounting Policies [Abstract]
Restatement does not require Recovery
Restatement Does Not Require Recovery [Text Block]
Reallocation of noncontrolling interest
Noncontrolling Interest, Increase (Decrease) from Subsidiary Equity Issuance
Noncontrolling Interest, Increase (Decrease) from Subsidiary Equity Issuance
Lease liabilities - operating leases (amounts related to VIEs of $167,297 and $0 at September 30, 2026 and December 31, 2025, respectively)
Lease Liabilities - Operating Leases
Operating Lease, Liability
Allocated net income for the period
Equity Profit Loss
Net Income.
Lease liabilities - finance leases (amounts related to VIEs of $21,193 and $21,074 at September 30, 2026 and December 31, 2025, respectively)
Finance Lease, Liability
Acquisition of noncontrolling interests in property partnerships
Proceeds from (Payment for) Other Financing Activity
Insider Trading Policies and Procedures Adopted
Insider Trading Policies and Procedures Adopted [Flag]
Reconciliation of Revenue to Rental Revenue
Reconciliation of Revenue to Rental Revenue [Table Text Block]
Reconciliation of Revenue to Rental Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) [Line Items]
PR II BXP Reston Gateway LLC
PR II BXP Reston Gateway LLC [Member]
PR II BXP Reston Gateway LLC
Commitments And Contingencies
Commitments and Contingencies Disclosure [Text Block]
Compensation Actually Paid vs. Net Income
Compensation Actually Paid vs. Net Income [Text Block]
Construction in progress
Construction in Progress, Gross
Lease
Lease
Operating Lease, Lease Income
All Adjustments to Compensation
All Adjustments to Compensation [Member]
Name of Property [Domain]
Name of Property [Domain]
Income Taxes
Income Tax, Policy [Policy Text Block]
Net cash provided by operating activities
Cash Provided by (Used in) Operating Activity, Including Discontinued Operation
4.628% unsecured senior notes
Four point six two eight percent unsecured senior notes [Member]
4.628% unsecured senior notes
Income Statement [Abstract]
Income Statement [Abstract]
Shares issued pursuant to stock purchase plan, shares
Stock Issued During Period, Shares, Employee Stock Purchase Plans
Document Transition Report
Document Transition Report
U.S. Treasury Bill, Term of Contract
U.S. Treasury Bill, Term of Contract
U.S. Treasury Bill, Term of Contract
Property partnerships
Noncontrolling Interest in Limited Partnerships
Noncontrolling Interest in Limited Partnerships
Gains from investments in securities
Gains (losses) from investments in securities
Gain (Loss) on Investments
Derivative, Swap Type
Derivative, Swap Type
Stock Appreciation Rights (SARs)
Stock Appreciation Rights (SARs) [Member]
Shady Grove Innovation District [Member]
Shady Grove Innovation District [Member]
Shady Grove Innovation District
Unconsolidated Joint Ventures [Member]
Unconsolidated Joint Ventures [Member]
Unconsolidated Joint Ventures [Member]
Buildings and improvements
Investment Building and Building Improvements
Intangible Asset, Finite-Lived, Acquired [Table]
Intangible Asset, Finite-Lived, Acquired [Table]
Lessor, Lease, Description [Line Items]
Lessor, Lease, Description [Line Items]
City Area Code
City Area Code
LTIP Unit Conversion Rate
LTIP Unit Conversion Rate
LTIP Unit Conversion Rate
Stock Issued During Period, Value, Conversion of Units
Stock Issued During Period, Value, Conversion of Units
Subsequent Events
Subsequent Events [Text Block]
Amortization of right of use assets - operating leases
Operating Lease, Right-of-Use Asset, Periodic Reduction
Per Occurrence Limit of Earthquake Insurance Seattle
Per Occurrence Limit of Earthquake Insurance Seattle
Per Occurrence Limit of Earthquake Insurance Seattle
Subtotal
Debt Instrument, Fair Value Disclosure
Name
Forgone Recovery, Individual Name
Non-GAAP Measure Description
Non-GAAP Measure Description [Text Block]
Distributions
Partners' Capital Account, Distributions
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)
Weighted Average Number Of Shares Outstanding After Allocation of Undistributed Earnings to Participating Securities Basic (in shares)
Entity [Domain]
Entity [Domain]
Finance Lease, Right-of-Use Asset, Reversal from Re-Assessment
Finance Lease, Right-of-Use Asset, Reversal from Re-Assessment
Finance Lease, Right-of-Use Asset, Reversal from Re-Assessment
Preferred stock / units, shares / units issued (in shares / units)
Preferred Stock, Shares Issued
Stock-Based Employee Compensation Plans
Share-Based Payment Arrangement [Policy Text Block]
Noncontrolling Interest, Increase from Sale of Parent Equity Interest
Noncontrolling Interest, Increase from Sale of Parent Equity Interest
Shares issued pursuant to stock purchase plan, value
Stock Issued During Period, Value, Employee Stock Purchase Plan
Proceeds from unsecured exchangeable senior notes
Proceeds from Convertible Debt
Restriction on redemption of OP Unit to Common Stock (in years)
Restriction On Redemption
Restriction on redemption of OP unit to Common Stock
Real Estate Held for Development and Sale, Policy
Real Estate Held for Development and Sale, Policy [Policy Text Block]
Cash and Cash Equivalents [Domain]
Cash and Cash Equivalents [Domain]
Stock based compensation expense
Share-Based Payment Arrangement, Expense
Measurement Basis [Axis]
Measurement Basis [Axis]
2.00% unsecured exchangeable senior notes
Two point zero zero percent unsecured exchangeable senior notes [Member]
Two point zero zero percent unsecured exchangeable senior notes
Cash and Cash Equivalents
Cash and Cash Equivalents, Policy [Policy Text Block]
250 Binney Street
Two Five Zero Binney Street [Member]
Two Five Zero Binney Street
Proceeds from sales of real estate
Proceeds from Real Estate and Real Estate Joint Ventures
Cash Equivalents, at Carrying Value
Cash Equivalents, at Carrying Value
Note B
Note B [Member]
Note B
Subsequent Event Type [Domain]
Subsequent Event Type [Domain]
Real estate contributed in exchange for investment in unconsolidated joint venture
Construction in progress, net deconsolidated
Construction in progress, net deconsolidated
Erroneously Awarded Compensation Recovery
Erroneously Awarded Compensation Recovery [Table]
Unvested MYLTIP Units and 2025 OPP Units [Member]
Unvested MYLTIP Units [Member]
Unvested 2018-2020 MYLTIPS[Member]
Entity Current Reporting Status
Entity Current Reporting Status
Net cash used in financing activities
Cash Provided by (Used in) Financing Activity, Including Discontinued Operation
Total Shareholder Return Amount
Total Shareholder Return Amount
Payments to Acquire Real Estate
Payments to Acquire Real Estate
Line of Credit Facility [Line Items]
Line of Credit Facility [Line Items]
Excess stock, par value
Excess Stock Par Or Stated Value Per Share
Excess Stock, Par or Stated Value Per Share
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
13150 Worldgate Drive
One three One Five Zero Worldgate Drive [Member]
13150 Worldgate Drive
Gateway Portfolio Holdings LLC
Gateway Portfolio Holdings LLC [Member]
Gateway Portfolio Holdings LLC
Adjustments to reconcile net income to net cash provided by operating activities:
Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract]
Cash flows from financing activities:
Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract]
Schedule of Real Estate Properties
Property, Plant, and Equipment, Lessor Asset under Operating Lease [Table Text Block]
Seattle
Seattle [Member]
Seattle
Lessor, Sales-type Leases
Lessor, Sales-type Leases [Text Block]
Intangible Asset, Finite-Lived, Class [Axis]
Intangible Asset, Finite-Lived, Class [Axis]
Excess stock, shares outstanding
Excess Stock, Shares Outstanding
Underlying Securities
Award Underlying Securities Amount
Properties
Name of Joint Venture Property
Name of Joint Venture Property
Comprehensive (Income) loss Attributable to Noncontrolling Interest
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest
Estimated Fair Value [Member]
Estimate of Fair Value Measurement [Member]
MYLTIP
MYLTIP [Member]
MYLTIP
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)
3.343 % unsecured senior notes
Three point three four three percent unsecured senior notes [Member]
3.343% unsecured senior notes [Member]
2100 M Street
Two One Zero Zero M Street [Member]
2100 M Street
Investment in non-real estate investments
Payment for (Proceeds from) for real estate sales from prior period
Payment for (Proceeds from) Other Investing Activity
Segment Reporting [Table]
Segment Reporting [Table]
Allowance for current expected credit losses
Provision for Loan, Lease, and Other Losses
Derivative, Number of Instruments Held
Derivative, Number of Instruments Held
Platform 16 Holdings LP [Member]
Platform 16
Platform Sixteen [Member]
Platform Sixteen [Member]
Lease, Cost
Lease, Cost [Table Text Block]
Cash
Cash [Member]
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Abstract]
All Trading Arrangements
All Trading Arrangements [Member]
Other Performance Measure, Amount
Other Performance Measure, Amount
Award Timing MNPI Considered
Award Timing MNPI Considered [Flag]
343 Madison Avenue
Three Four Three Madison Avenue [Member]
Three Four Three Madison Avenue
Current Fiscal Year End Date
Current Fiscal Year End Date
Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain]
Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain]
Unconsolidated Properties
Unconsolidated Properties [Member]
Partners' Capital (General and Limited Partners) [Member]
Boston Properties Limited Parntership [Member]
Boston Properties Limited Parntership [Member]
Related to prior period sales
Related to prior period sales [Member]
Related to prior period sales
Non-PEO NEO Average Total Compensation Amount
Non-PEO NEO Average Total Compensation Amount
Derivative [Line Items]
Derivative [Line Items]
360 PAS Holdco LLC
360 Park Avenue South
Three Six Zero PAS Holdco LLC [Member]
Three Six Zero PAS Holdco LLC
Cumulative Effect, Period of Adoption [Domain]
Cumulative Effect, Period of Adoption [Domain]
Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year
Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member]
Entity File Number
Entity File Number
Office Building [Member]
Office Building [Member]
Net activity from stock option and incentive plan, value
Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture
Company's share of Net Operating Income
Net Operating Income
The net result for the period of deducting property operating expenses from property operating revenues.
Issuance of notes receivable (including related party)
Origination of Notes Receivable from Related Parties
Recovery of Erroneously Awarded Compensation Disclosure [Line Items]
Unsecured senior notes, net
Senior Notes
Senior Notes
Measure:
Measure [Axis]
Investments In Unconsolidated Joint Ventures
Equity Method Investments and Joint Ventures Disclosure [Text Block]
Common units of the Operating Partnership
Noncontrolling Interest in Operating Partnerships
Treasury common stock at cost, shares
Treasury Stock, Common, Shares
Long-Lived Asset, Held-for-Sale, Type [Axis]
Long-Lived Asset, Held-for-Sale, Type [Axis]
Safeco Partner Entity Two
Safeco Partner Entity Two [Member]
Safeco Partner Entity Two
Total adjustments
Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity
Equity Components [Axis]
Equity Components [Axis]
Transaction costs
Transaction costs
Other Cost and Expense, Operating
Tenant improvements
Payment for Leasehold Improvement, Lessor, Investing Activity
Related Party
Related Party [Member]
Cumulative Effect, Period of Adoption [Axis]
Cumulative Effect, Period of Adoption [Axis]
Asset Acquisition
Asset Acquisition [Table Text Block]
501 K Street LLC [Member]
five zero one K Street LLC [Member]
501 K Street LLC [Member]
WP Project Developer LLC [Member]
Wp Project Developer Llc [Member]
WP Project Developer LLC [Member]
Entity Interactive Data Current
Entity Interactive Data Current
Net Income Attributable to Noncontrolling Interest
Net Income (Loss) Attributable to Noncontrolling Interest
Reston Next Retail
Reston Next Retail [Member]
Reston Next Retail
Redemption of operating partnership units to common stock, shares
Conversion of redeemable partnership units
Stock Issued During Period, Shares, Conversion of Units
Entity Small Business
Entity Small Business
Comprehensive Income (Loss) Attributable to the Company
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Debt Instrument, Unamortized Discount
Debt Instrument, Unamortized Discount
Title of 12(g) Security
Title of 12(g) Security
Excess stock, shares issued
Excess Stock, Shares Issued
MNPI Disclosure Timed for Compensation Value
MNPI Disclosure Timed for Compensation Value [Flag]
One OP unit is equivalent to one share of Common Stock (in shares)
Common Stock Conversion Rate
Common Stock Conversion Rate
Skymark
Skymark [Member]
Skymark
Document Type
Document Type
Acquisition of real estate upon consolidation of unconsolidated joint ventures (net of cash)
Payments to Acquire Businesses, Net of Cash Acquired
Loss from early extinguishment of debt
Loss from early extinguishment of debt
Loss from early extinguishment of debt
Gain (Loss) on Extinguishment of Debt
Joint Venture Partner [Member]
Joint Venture Partner [Member]
Joint Venture Partner [Member]
Non-cash portion of interest expense
Paid-in-Kind Interest
unvested MYLTIP distributions as compared to total distributions (percentage)
unvested MYLTIP and 2025 OPP distributions as compared to total distributions (percentage)
unvested MYLTIP distributions as compared to total distributions (percentage)
Capitalized operating lease costs
Capitalized operating lease costs
Capitalized operating lease costs
200 Fifth Avenue JV LLC
Two Zero Zero Fifth Avenue JV LLC [Member]
Two Zero Zero Fifth Avenue JV LLC
Subsequent Event [Line Items]
Subsequent Event [Line Items]
Share-Based Compensation Arrangements by Share-Based Payment Award, Restricted Stock Units, Vested and Expected to Vest
Share-Based Compensation Arrangements by Share-Based Payment Award, Restricted Stock Units, Vested and Expected to Vest [Table Text Block]
Statement of Stockholders' Equity [Abstract]
Statement of Stockholders' Equity [Abstract]
Local Phone Number
Local Phone Number
Net Operating Income: % of Grand Totals
Percentage Of Total Net Operating Income
Percentage Of Total Net Operating Income
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
Liabilities for Contingent Guarantees
Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Commitments and contingencies (See Note 8)
Commitments and Contingencies
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]
Residential Tower Developer LLC [Member]
Residential Tower Developer LLC [Member]
Residential Tower Developer LLC [Member]
Changed Peer Group, Footnote
Changed Peer Group, Footnote [Text Block]
2030
Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four
5.842% unsecured senior notes
Five point Eight Four Two Percent [Member]
Five point Eight Four Two Percent
Executive Category:
Executive Category [Axis]
Receivable Type [Axis]
Receivable Type [Axis]
Rental Revenue: % of Grand Totals
Percentage Of Total Revenue
These are percentages not monetary value
Above and below market rent adjustments, net
Above And Below Market Rent Adjustments
Above And Below Market Rent Adjustments
Unvested Restricted stock and LTIP Units [Member]
Unvested Restricted stock and LTIP Units [Member]
Unvested Restricted stock and LTIP Units [Member]
LIABILITIES AND EQUITY
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Liabilities and Equity [Abstract]
Commitments And Contingencies Disclosure [Table]
Commitments And Contingencies Disclosure [Table]
Commitments and Contingencies Disclosure [Table]
Non-PEO NEO Average Compensation Actually Paid Amount
Non-PEO NEO Average Compensation Actually Paid Amount
Redemption of OP Unit equivalent to Common Stock (in shares)
OP Unit Equivalence To Common Stock
One OP Unit is equivalent to one common stock (share).
Total Office Properties [Member]
Total Office Properties [Member]
Total Office Properties [Member].
Supplemental disclosures:
Supplemental Cash Flow Information [Abstract]
Amortization of interest rate contracts (1)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax
Accounts payable and accrued expenses (amounts related to VIEs of $137,831 and $88,849 at September 30, 2026 and December 31, 2025, respectively)
Accounts payable and accrued expenses
Accounts Payable and Accrued Liabilities
PEO Name
PEO Name
Allocated net income for the period
Net income allocable to general and limited partner units
Net Income Allocable To General And Limited Partner Units
Property, Plant and Equipment, Type [Axis]
Long-Lived Asset, Class [Axis]
Repayments of mortgage notes payable
Repayments of Secured Debt
Stock Price or TSR Estimation Method
Stock Price or TSR Estimation Method [Text Block]
Entity Tax Identification Number
Entity Tax Identification Number
6.924% unsecured senior notes
Six point nine two four percent unsecured senior notes [Member]
Six point nine two four percent unsecured senior notes
Effective portion of interest rate contracts
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax
Prepaid expenses and other assets (amounts related to VIEs of $97,856 and $14,509 at September 30, 2026 and December 31, 2025, respectively)
Prepaid Expense and Other Assets
Prepaid Expense and Other Assets
500 North Capitol Venture LLC [Member]
Five Zero Zero North Capitol Llc [Member]
Five Zero Zero North Capitol LLC [Member].
Separate Unrestricted Cash For Deferred Compensation Plan.
Separate Unrestricted Cash For Deferred Compensation Plan.
Separate Unrestricted Cash For Deferred Compensation Plan.
Basis differential
Income Statement Basis Differential
Income Statement Basis Differential
Revenue Recognition
Revenue [Policy Text Block]
Fixed contractual payments
Operating Lease, Lease Income, Lease Payments
Entity Incorporation, State or Country Code
Entity Incorporation, State or Country Code
Aggregate Erroneous Compensation Not Yet Determined
Aggregate Erroneous Compensation Not Yet Determined [Text Block]
Material Terms of Trading Arrangement
Material Terms of Trading Arrangement [Text Block]
Cash held in escrows (amounts related to VIEs of $5,905 and $10,319 at September 30, 2026 and December 31, 2025, respectively)
Cash held in escrows, beginning of period
Cash held in escrows,end of period
Restricted Cash and Cash Equivalent, Current
Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year
Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member]
Organization
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]
Comprehensive income (loss)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest
Noncontrolling interests:
Noncontrolling Interest Items [Abstract]
Debt Instrument [Axis]
Debt Instrument [Axis]
Subsequent Event [Table]
Subsequent Event [Table]
Non-cash compensation expense
Share-Based Payment Arrangement, Noncash Expense
Land
Land
Tenant leasing costs
Lease, Cost
767 Venture, LLC [Member]
Seven Six Seven Venture Llc [Member]
Seven Six Seven Venture LLC [Member]
Gains on sales of real estate
Gains on sales of real estate
Gain (loss) on sale
Loss on sale of real estate
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property
Earnings Per Share, Basic
Earnings Per Share, Basic
Podium Venture LLC [Member]
Podium Venture LLC [Member]
Podium Venture LLC [Member]
Insider Trading Arrangements [Line Items]
Deferred financing costs
Payments of Financing Costs
Document Annual Report
Document Annual Report
Rental Expenses: % Of Grand Totals
Percentage Of Total Rental Expenses
Percentage Of Total Rental Expenses.
Redeemable partnership units— 14,722,303 and 15,590,009 common units and 3,102,888 and 2,662,140 long term incentive units outstanding at redemption value at September 30, 2026 and December 31, 2025, respectively
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount
Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table
Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member]
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Terrorism
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Terrorism
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Terrorism
Real Estate, Type of Property [Axis]
Real Estate, Type of Property [Axis]
Debt Instrument, Unused Borrowing Capacity, Amount
Debt Instrument, Unused Borrowing Capacity, Amount
Unsecured term loans, net
Unsecured term loan, net
Other Borrowings
Fair Value Measurement [Domain]
Fair Value Measurement [Domain]
Compensation Actually Paid vs. Company Selected Measure
Compensation Actually Paid vs. Company Selected Measure [Text Block]
Cover [Abstract]
Cover [Abstract]
Reclassification
Reclassification, Comparability Adjustment [Policy Text Block]
Documents Incorporated by Reference
Documents Incorporated by Reference [Text Block]
Number of buildings
number of buildings
number of buildings
Equity Awards Adjustments
Equity Awards Adjustments [Member]
Asset Acquisition [Line Items]
Asset Acquisition [Line Items]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Lessor, Operating Lease, Payments to be Received, Maturity
Lessor, Operating Lease, Payment to be Received, Maturity [Table Text Block]
Other liabilities
Increase (Decrease) in Other Operating Liabilities
Derivative, Maturity Date
Derivative, Contract End Date
General Partners' Capital Account, Units Outstanding (in units)
General Partners' Capital Account, Units Outstanding
2031
Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Five
Equity / Capital:
Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
General and administrative
General and administrative expense
General and Administrative Expense
Preferred stock, shares authorized
Preferred Stock, Shares Authorized
Derivatives, Fair Value [Line Items]
Derivatives, Fair Value [Line Items]
Number of real estate properties
Number of Real Estate Properties
Class of Stock [Domain]
Class of Stock [Domain]
Statement of Cash Flows [Abstract]
Statement of Cash Flows [Abstract]
Other Commitment
Other Commitment
Aggregate Available
Trading Arrangement, Securities Aggregate Available Amount
6.619% unsecured senior notes
Six point Six One Nine Percent [Member]
Six point Six One Nine Percent
Investment in Securities
Investment, Policy [Policy Text Block]
MYLTIP Performance Period Performance
Share-Based Compensation Arrangements by Share-Based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block]
Pay vs Performance Disclosure
Pay vs Performance Disclosure [Table]
Gain (Loss) on Sale of Derivatives
Gain (Loss) on Sale of Derivatives
Entity Filer Category
Entity Filer Category
Noncontrolling interests in property partnerships
Noncontrolling Interest in Net Income (Loss) Limited Partnerships, Nonredeemable
Noncontrolling Interest in Net Income (Loss) Limited Partnerships, Nonredeemable
Accounting Standards Update 2023-05
Accounting Standards Update 2023-05 [Member]
General Partner [Member]
General Partner [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage
Distributions of net cash flow from operations of unconsolidated joint ventures
Proceeds from Equity Method Investment, Distribution
Noncontrolling Interest, Outstanding
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Stock by Class [Table]
Stock, Class of Stock [Table]
Net income (loss)
Net Income (Loss)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest
Statement of Partners' Capital [Abstract]
Statement of Partners' Capital [Abstract]
Property insurance program per occurrence limits
Insurance Policy Limit
Insurance Policy Limit
Interest Rate Cap
Interest Rate Cap [Member]
Senior Notes
Senior Notes [Member]
Entity Address, Address Line One
Entity Address, Address Line One
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability
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]
Proceeds from note receivables (including related party)
Proceeds from Mortgage Deposits
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Primary Beneficiary [Member]
Loan Restructuring Modification [Domain]
Loan Restructuring Modification [Domain]
Annual aggregate limit of the earthquake insurance which covers San Francisco and Los Angeles regions
Annual Aggregate Limit Of Earth Quake Insurance San Francisco and Los Angeles
Annual Aggregate Limit Of Earth Quake Insurance San Francisco and Los Angeles
Statement [Table]
Statement [Table]
Segment Reconciling Items
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment [Member]
Stock Issued During Period, Value, Restricted Stock Award, Gross
Stock Issued During Period, Value, Restricted Stock Award, Gross
Mortgage note payable converted to unsecured term loan
Debt Conversion, Converted Instrument, Amount
Deferred Compensation, Excluding Share-Based Payments and Retirement Benefits
Deferred Compensation, Excluding Share-Based Payments and Retirement Benefits [Member]
Colorado Center, Gateway Commons and Safeco Plaza
Colorado Center, Gateway Commons and Safeco Plaza [Member]
Colorado Center, Gateway Commons and Safeco Plaza
Cash and Cash Equivalents [Axis]
Cash and Cash Equivalents [Axis]
Note A
Note A [Member]
Note A
Forfeitures, in units
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Forfeitures
Summary Of Significant Accounting Policies
Basis of Presentation and Significant Accounting Policies [Text Block]
Derivative Instruments and Hedging Activities Disclosure [Abstract]