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Consolidated and unconsolidated real estate joint ventures (Details) $ in Thousands | 1 Months Ended | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | --- | ---
Mar. 31, 2025 USD ($) | Sep. 30, 2025 USD ($) | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) | Sep. 30, 2024 USD ($) | Jul. 31, 2025 USD ($) | Jun. 30, 2025 ft² property
Schedule of Equity Method Investments |  |  |  |  |  |  |
Gain on sales of real estate |  | $ 9,366 | $ 27,114 | $ 22,531 | $ 27,506 |  |
Noncash, Acquisition of our partner’s noncontrolling interest in 199 East Blaine Street |  |  |  | 96,543 | 0 |  |
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests |  | 48,710 |  | 48,710 | 250 |  |
Proceeds from sales of real estate |  |  |  | 227,105 | 229,790 |  |
Payments to noncontrolling interests |  |  |  | 204,543 | 231,072 |  |
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders |  | 241,924 | 59,000 | 372,188 | 194,871 |  |
Greater Boston |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures | $ 10,400 |  |  |  |  |  |
Additional Paid-In Capital |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders |  | 66,317 | 0 | 73,365 | 8,084 |  |
Noncontrolling Interests |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests |  | 48,710 |  | 48,710 | 250 |  |
Payments to noncontrolling interests |  |  |  | 186,800 | 179,100 |  |
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders |  | $ 175,607 | $ 59,000 | $ 298,823 | $ 186,787 |  |
Noncontrolling Interests | Greater Boston |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders | $ 7,000 |  |  |  |  |  |
1655 and 1725 Third Street |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Equity Method Investment, Ownership Percentage |  | 10.00% |  | 10.00% |  |  |
1450 Research Boulevard |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Equity Method Investment, Ownership Percentage |  | 73.20% |  | 73.20% |  |  |
101 West Dickman Street |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Equity Method Investment, Ownership Percentage |  | 58.40% |  | 58.40% |  |  |
50 and 60 Binney Street | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 34.00% |  | 34.00% |  |  |
75/125 Binney Street | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 40.00% |  | 40.00% |  |  |
100 and 225 Binney Street and 300 Third Street | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 30.00% |  | 30.00% |  |  |
15 Necco Street | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 56.70% |  | 56.70% |  |  |
285, 299, 307, and 345 Dorchester Avenue | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 60.00% |  | 60.00% |  |  |
Alexandria Center for Science and Technology - Mission Bay | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 25.00% |  | 25.00% |  |  |
601, 611, 651, 681, 685, and 701 Gateway Boulevard | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 50.00% |  | 50.00% |  |  |
751 Gateway Boulevard | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 51.00% |  | 51.00% |  |  |
211 and 213 East Grand Avenue | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 30.00% |  | 30.00% |  |  |
500 Forbes Boulevard | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 10.00% |  | 10.00% |  |  |
Alexandria Center® for Life Science – Millbrae | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 48.50% |  | 48.50% |  |  |
3215 Merryfield Row | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 30.00% |  | 30.00% |  |  |
Campus Point by Alexandria | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 55.00% |  | 55.00% |  |  |
5200 Illumina Way | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 51.00% |  | 51.00% |  |  |
9625 Towne Centre Drive | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 30.00% |  | 30.00% |  |  |
SD Tech by Alexandria | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 50.00% |  | 50.00% |  |  |
Summers Ridge Science Park | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 30.00% |  | 30.00% |  |  |
1201 and 1208 Eastlake Avenue East | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 30.00% |  | 30.00% |  |  |
400 Dexter Avenue North | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 30.00% |  | 30.00% |  |  |
800 Mercer Street | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 60.00% |  | 60.00% |  |  |
99 Coolidge Avenue |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest in Joint Ventures |  |  |  |  |  | $ 42,000 |
Redeemable Noncontrolling Interest, Equity, Fair Value |  | $ 48,700 |  | $ 48,700 |  |  |
Redeemable Noncontrolling Interest, Accretion Rate |  | 4.05% |  | 4.05% |  |  |
Redeemable Noncontrolling Interest, Equity, Accrued Distribution |  | $ 340 |  | $ 340 |  |  |
99 Coolidge Avenue | Additional Paid-In Capital |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests |  | 6,700 |  |  |  |  |
Pacific Technology Park |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Proceeds from Divestiture of Interest in Consolidated Subsidiaries |  | 96,000 |  |  |  |  |
Number of real estate properties | property |  |  |  |  |  |  | 5
Gain on sales of real estate |  | 9,300 |  | 9,290 |  |  |
Noncontrolling Interest In Joint Ventures, Derecognized |  | $ 82,400 |  | $ 82,400 |  |  |
Pacific Technology Park | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 50.00% |  | 50.00% |  |  | 50.00%
Subsidiary, Ownership Percentage, Noncontrolling Owner |  |  |  |  |  |  | 50.00%
199 East Blaine Street |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest in Joint Ventures |  | $ 30,300 |  | $ 30,300 |  |  |
Area of real estate property | ft² |  |  |  |  |  |  | 115,084
Noncash, Acquisition of our partner’s noncontrolling interest in 199 East Blaine Street |  |  |  | $ 94,400 |  |  |
199 East Blaine Street | Additional Paid-In Capital |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests |  | $ 66,300 |  |  |  |  |
199 East Blaine Street | Alexandria |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Noncontrolling Interest, Ownership Percentage by Parent |  | 100.00% |  | 100.00% |  |  | 30.00%
Subsidiary, Ownership Percentage, Noncontrolling Owner |  |  |  |  |  |  | 70.00%
Pacific Technology Park and 199 East Blaine Street |  |  |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |  |  |
Proceeds from sales of real estate |  | $ 1,600 |  |  |  |  |

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