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