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Real Estate (Narrative) (Details) $ in Thousands |  |  | 3 Months Ended | 6 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 31, 2024 USD ($) | Jan. 08, 2024 USD ($) ft² | Jun. 30, 2024 USD ($) ft² Real_Estate_Properties | Jun. 30, 2023 USD ($) | Jun. 30, 2024 USD ($) ft² Real_Estate_Properties | Jun. 30, 2024 USD ($) ft² Real_Estate_Properties | Jun. 30, 2023 USD ($) | May 07, 2024 USD ($) ft² | Apr. 05, 2024 ft² | Feb. 12, 2024 ft² apartments | Jan. 07, 2024 USD ($) | Dec. 31, 2023 USD ($)
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Total revenue |  |  |  | $ 850,482 | $ 817,153 |  | $ 1,689,921 | $ 1,620,353 |  |  |  |  |
Net Income (Loss) |  |  |  | 79,615 | 104,299 |  | 159,498 | 182,215 |  |  |  |  |
Carying value of the Company's investment in unconsolidated joint ventures |  |  |  | 1,418,817 |  | $ 1,418,817 | 1,418,817 |  |  |  |  |  | $ 1,377,319
Impairment loss |  |  |  | $ 0 | $ 0 |  | $ 13,615 | $ 0 |  |  |  |  |
901 New York Avenue LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage | [1] |  |  |  |  |  |  |  |  |  |  |  | 25.00%
Construction in Progress |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  | 3,100,000 |  | 3,100,000 | 3,100,000 |  |  |  |  |  |
Number of real estate properties | Real_Estate_Properties |  |  |  | 10 |  | 10 | 10 |  |  |  |  |  |
901 New York Avenue |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  | 524,000 |  |  |  |  |  |  |  |  |  |
Payments to Acquire Investments |  |  | $ 10,000 |  |  |  |  |  |  |  |  |  |
Net Working Capital, Including Cash Acquired from Acquisition |  |  | 7,100 |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale / consolidation |  |  | 21,800 |  |  |  |  |  |  |  |  |  |
Total revenue |  |  |  |  |  | $ 16,300 |  |  |  |  |  |  |
Net Income (Loss) |  |  |  |  |  | $ (4,600) |  |  |  |  |  |  |
Asset Acquisition, Consideration Transferred |  |  | 20,000 |  |  |  |  |  |  |  |  |  |
901 New York Avenue | Unconsolidated Properties |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale / consolidation |  |  | 21,800 |  |  |  |  |  |  |  |  |  |
901 New York Avenue | 901 New York Avenue LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Carying value of the Company's investment in unconsolidated joint ventures |  |  |  |  |  |  |  |  |  |  |  | $ (11,800) |
Investments in Affiliates, Subsidiaries, Associates, and Joint Ventures, Fair Value Disclosure |  |  | 10,000 |  |  |  |  |  |  |  |  |  |
901 New York Avenue | 901 New York Avenue LLC [Member] | Unconsolidated Properties |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  |  |  |  |  |  |  |  | 50.00% |
901 New York Avenue | Mortgages [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  | 207,100 |  |  |  |  |  |  |  |  |  |
Assumption of mortgage notes payable |  |  | $ 207,100 |  |  |  |  |  |  |  |  |  |
901 New York Avenue | Joint Venture Partner [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  | 50.00% |  |  |  |  |  |  |  |  |  |
901 New York Avenue | Joint Venture Partner [Member] | 901 New York Avenue LLC [Member] | Unconsolidated Properties |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  | 50.00% |  |  |  |  |  |  |  |  |  |
Shady Grove Innovation District [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  | 143,000 |  |  |  |
Impairment loss |  | $ 13,600 |  |  |  |  | $ 13,600 |  |  |  |  |  |
Number of real estate properties |  |  |  |  |  |  |  |  | 2 |  |  |  |
Contractual Sales Price |  |  |  |  |  |  |  |  | $ 24,800 |  |  |  |
760 Boylston Street |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  |  | 118,000 |  |  |
121 Broadway | Construction in Progress | Residential Properties [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  |  |  | 492,000 |  |
Number of Units in Real Estate Property | apartments |  |  |  |  |  |  |  |  |  |  | 439 |  |
[1] | At December 31, 2023, the Company’s economic ownership was approximately 50%. On January 8, 2024, the Company completed the acquisition of its joint venture partner’s 50% economic ownership interest for a gross purchase price of $10.0 million, as described in Note 3 and this Note 5. Since then, the Company accounts for its assets, liabilities and operations on a consolidated basis.

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