Revenues - Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($) community	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) community	Jun. 30, 2023 USD ($)
Disaggregation of Revenue [Line Items]
Rental and other property	$ 439,782	$ 413,265	$ 863,997	$ 822,921
Management and other fees from affiliates	2,573	2,778	5,286	5,543
Revenues	$ 442,355	416,043	$ 869,283	828,464
Apartment communities owned (in communities) | community	255		255
Rental income
Disaggregation of Revenue [Line Items]
Rental and other property	$ 432,141	407,786	$ 849,377	812,421
Other property
Disaggregation of Revenue [Line Items]
Rental and other property	7,641	5,479	14,620	10,500
Rental and other property revenues
Disaggregation of Revenue [Line Items]
Rental and other property	439,782	413,265	863,997	822,921
Rental and other property revenues | Same-property
Disaggregation of Revenue [Line Items]
Rental and other property	$ 414,845	401,065	$ 824,664	796,585
Occupancy threshold for classification as stabilized	90.00%		90.00%
Rental and other property revenues | Acquisitions
Disaggregation of Revenue [Line Items]
Rental and other property	$ 12,824	225	$ 14,422	225
Rental and other property revenues | Redevelopment
Disaggregation of Revenue [Line Items]
Rental and other property	1,565	1,595	3,106	3,132
Rental and other property revenues | Non-residential/other, net
Disaggregation of Revenue [Line Items]
Rental and other property	$ 11,059	11,055	$ 22,379	23,078
Apartment communities owned (in communities) | community	2		2
Rental and other property revenues | Straight line rent concession
Disaggregation of Revenue [Line Items]
Rental and other property	$ (511)	(675)	$ (574)	(99)
Rental and other property revenues | Operating Segments | Southern California
Disaggregation of Revenue [Line Items]
Rental and other property	186,604	169,857	362,606	336,734
Rental and other property revenues | Operating Segments | Northern California
Disaggregation of Revenue [Line Items]
Rental and other property	172,615	166,459	341,454	330,187
Rental and other property revenues | Operating Segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Rental and other property	73,782	70,217	145,695	140,255
Rental and other property revenues | Other real estate assets
Disaggregation of Revenue [Line Items]
Rental and other property	$ 6,781	$ 6,732	$ 14,242	$ 15,745