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Organization and Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands | 1 Months Ended | 3 Months Ended | 9 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jul. 31, 2024 USD ($) ApartmentUnits | Sep. 30, 2024 USD ($) Properties Property Community State shares | Sep. 30, 2023 USD ($) shares | Sep. 30, 2024 USD ($) Properties Property Community State shares | Sep. 30, 2023 USD ($) shares | Dec. 31, 2027 Property | Dec. 31, 2026 Property | Dec. 31, 2025 Property | Dec. 31, 2024 Property | Dec. 31, 2023 USD ($) shares
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
General Partners' Capital Account, Units Outstanding | shares |  | 116,880,291 | 116,686,730 | 116,880,291 | 116,686,730 |  |  |  |  |
Number of Real Estate Properties | Community |  | 293 |  | 293 |  |  |  |  |  |
Number of units under development community | 239 | 2,762 |  | 2,762 |  |  |  |  |  |
Initial funding on real estate land and land development | $ 70,500 |  |  |  |  |  |  |  |  |
Development costs | $ 112,000 |  |  |  |  |  |  |  |  |
Development and capital improvements in progress |  | $ 499,619 |  | $ 499,619 |  |  |  |  |  | $ 385,405
Number of States in which Entity Operates | State |  | 16 |  | 16 |  |  |  |  |  |
Consolidated assets |  | $ 11,756,252 |  | $ 11,756,252 |  |  |  |  |  | 11,484,503
Consolidated liabilities |  | 5,602,140 |  | 5,602,140 |  |  |  |  |  | 5,185,381
Real Estate Investments, Joint Ventures |  | $ 31,600 |  | $ 31,600 |  |  |  |  |  |
Percentage Of Rental Revenue From Leasing Of Apartment Homes |  |  |  | 94.00% |  |  |  |  |  |
Percentage Of Reimbursable Revenue From Leasing Of Apartment Homes |  |  |  | 5.00% |  |  |  |  |  |
Percentage of Rental Revenue and Other Income From Non-leasing Activities |  |  |  | 1.00% |  |  |  |  |  |
Operating Lease, Right-of-Use Asset, Statement of Financial Position |  | Other assets |  | Other assets |  |  |  |  |  |
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] |  | Accrued expenses and other liabilities |  | Accrued expenses and other liabilities |  |  |  |  |  |
Operating Lease, Right-of-Use Asset |  | $ 41,000 |  | $ 41,000 |  |  |  |  |  | 42,500
Right-of-use Lease, Liability |  | 26,454 |  | 26,454 |  |  |  |  |  | 27,300
Marketable equity securities received |  | 0 | $ 7,700 | 0 | $ 7,700 |  |  |  |  |
Net proceeds from sale of marketable equity securities |  | 3,300 |  | 9,975 | 0 |  |  |  |  |
Net realized / unrealized gain on sale |  | 2,700 |  | 8,300 |  |  |  |  |  |
Marketable equity securities |  | 3,300 |  | 3,300 |  |  |  |  |  | 18,600
Marketable Equity Securities [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Unrealized losses |  | (1,200) | (7,100) | (5,400) | (500) |  |  |  |  |
Limited Partnership [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Investment Income |  | 500 | $ 600 | 9,000 | $ 1,300 |  |  |  |  |
Other Assets [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Real Estate Investments, Joint Ventures |  | 57,100 |  | 57,100 |  |  |  |  |  | 46,500
Real Estate [Member] | Post Massachusetts Avenue [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Real Estate Investments, Joint Ventures |  | $ 41,700 |  | $ 41,700 |  |  |  |  |  | $ 42,000
Maximum [Member] | Accounting Standards Update 2016-02 [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Operating lease, term of contract |  | 1 year |  | 1 year |  |  |  |  |  |
Development Properties [Member] | Scenario Forecast [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Number of Real Estate Properties | Property |  |  |  |  |  | 1 | 3 | 2 | 2 |
Retail [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Number of Real Estate Properties | Property |  | 35 |  | 35 |  |  |  |  |  |
M A A L P [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest |  |  |  | 97.40% | 97.40% |  |  |  |  |
Limited Partnership [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
General Partners' Capital Account, Units Outstanding | shares |  | 116,880,291 |  | 116,880,291 |  |  |  |  |  | 116,694,124
Number of Real Estate Properties | Property |  | 1 |  | 1 |  |  |  |  |  |
Development and capital improvements in progress |  | $ 499,619 |  | $ 499,619 |  |  |  |  |  | $ 385,405
Consolidated assets |  | 11,756,252 |  | 11,756,252 |  |  |  |  |  | 11,484,503
Consolidated liabilities |  | 5,602,159 |  | 5,602,159 |  |  |  |  |  | 5,185,400
Net proceeds from sale of marketable equity securities |  |  |  | 9,975 | $ 0 |  |  |  |  |
Limited Partnership [Member] | Real Estate [Member] | Variable Interest Entity Primary Beneficiary [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Consolidated assets |  | 443,900 |  | 443,900 |  |  |  |  |  | 265,100
Consolidated liabilities |  | $ 27,300 |  | $ 27,300 |  |  |  |  |  | $ 12,900
Limited Partnership [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Percentage of ownership interests of all consolidated subsidiaries (percent) |  | 80.00% |  | 80.00% |  |  |  |  |  |
Limited Partnership [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Percentage of ownership interests of all consolidated subsidiaries (percent) |  | 100.00% |  | 100.00% |  |  |  |  |  |
Limited Partnership [Member] | Development Properties [Member] | Costs Incurred To Date [Member] |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |
Development and capital improvements in progress |  | $ 610,400 |  | $ 610,400 |  |  |  |  |  |

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