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v3.25.4

Related Party Transactions (Details) $ in Thousands |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
Oct. 17, 2025 USD ($) | Oct. 16, 2025 USD ($) | Dec. 31, 2025 USD ($) ft² nonemployeedirectors shares | Dec. 31, 2024 USD ($) shares | Dec. 31, 2023 USD ($) | Jun. 05, 2023 USD ($) ft²
Related Party Transaction [Line Items] |  |  |  |  |  |
Interest and Other Income |  |  | $ 35,784 | $ 60,199 | $ 69,964 |
Number Of Non Employee Directors Electing To Receive Deferred Stock Units | nonemployeedirectors |  |  | 7 |  |  |
Separate Unrestricted Cash For Deferred Compensation Plan. |  |  | $ 44,400 | 39,400 |  |
Liability for directors |  |  | $ 480,017 | $ 401,874 |  |
Reedemable deferred stock units, units | shares |  |  | 111,701 | 128,227 |  |
500 North Capitol Street, NW | Unconsolidated Properties |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  | 231,000
3 Hudson Boulevard [Member] | Unconsolidated Properties |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 3.61% |  |  |  |
Boston Properties Limited Partnership |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Debt |  |  | $ 9,850,000 |  |  |
Interest and Other Income |  |  | 35,784 | $ 60,199 | 69,964 |
Liability for directors |  |  | $ 480,017 | $ 401,874 |  |
Reedemable deferred stock units, units | shares |  |  | 111,701 | 128,227 |  |
3 Hudson Boulevard [Member] |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Ownership Percentage |  |  | 25.00% |  |  |
Net Rentable Area (in sf) | ft² |  |  | 2,000,000.0 |  |  |
500 North Capitol Venture LLC [Member] |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Ownership Percentage |  |  | 30.00% |  |  |
500 North Capitol Venture LLC [Member] | 500 North Capitol Street, NW | Unconsolidated Properties |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Ownership Percentage |  |  |  |  |  | 30.00%
Related Party | 3 Hudson Boulevard [Member] | Unconsolidated Properties | Notes Receivables [Member] |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Related party note receivable, net |  | $ 80,000 |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 7.25% | 3.61% |  |  |  |
Real Estate Brokerage Firm | Related Party |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Operating Costs and Expenses |  |  |  |  | 500 |
Related Party |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Related party note receivable, net |  |  | $ 28,346 | $ 88,779 |  |
Separate Unrestricted Cash For Deferred Compensation Plan. |  |  | 800 | 700 |  |
Liability for directors |  |  | 800 | 700 |  |
Related Party | 500 North Capitol Street, NW | Unconsolidated Properties |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Debt |  |  |  |  |  | $ 105,000
Debt, Weighted Average Interest Rate |  |  |  |  |  | 6.83%
Related Party | 500 North Capitol Street, NW | Unconsolidated Properties | Notes Receivables [Member] |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Related party note receivable, net |  |  |  |  |  | $ 10,500
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  | 8.03%
Interest and Other Income |  |  | 900 | 800 | 600 |
Related Party | 3 Hudson Boulevard [Member] |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Debt Instrument, Decrease, Forgiveness | $ 5,800 |  |  |  |  |
Related Party | 3 Hudson Boulevard [Member] | Unconsolidated Properties |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Debt |  |  | 18,400 |  |  |
Related Party | 3 Hudson Boulevard [Member] | Unconsolidated Properties | Maximum [Member] |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Debt | $ 50,000 |  |  |  |  |
Related Party | Boston Properties Limited Partnership |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Related party note receivable, net |  |  | 28,346 | 88,779 |  |
Related Party | 3 Hudson Boulevard [Member] |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Interest and Other Income |  |  | $ 6,400 | $ 11,600 | $ 8,900 |

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