Revenues - Disaggregation of Revenue (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) community	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Rental and other property	$ 1,764,185	$ 1,658,264	$ 1,595,675
Management and other fees from affiliates	10,265	11,131	11,139
Total revenues	$ 1,774,450	1,669,395	1,606,814
Apartment communities owned (in communities) | community	255
Operating segments | Southern California
Disaggregation of Revenue [Line Items]
Rental and other property	$ 744,004	682,116	646,252
Operating segments | Northern California
Disaggregation of Revenue [Line Items]
Rental and other property	677,393	642,658	615,677
Operating segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Rental and other property	295,002	282,092	271,248
Other real estate assets
Disaggregation of Revenue [Line Items]
Rental and other property	47,786	51,398	62,498
Rental income
Disaggregation of Revenue [Line Items]
Rental and other property	1,735,411	1,636,070	1,573,368
Other property
Disaggregation of Revenue [Line Items]
Rental and other property	28,774	22,194	22,307
Rental and other property
Disaggregation of Revenue [Line Items]
Rental and other property	1,764,185	1,658,264	1,595,675
Rental and other property | Same-property
Disaggregation of Revenue [Line Items]
Rental and other property	$ 1,636,531	1,585,007	1,513,864
Occupancy threshold for classification as stabilized	90.00%
Rental and other property | Acquisitions
Disaggregation of Revenue [Line Items]
Rental and other property	$ 58,158	1,037	0
Rental and other property | Redevelopment
Disaggregation of Revenue [Line Items]
Rental and other property	6,519	6,232	5,765
Rental and other property | Non-residential/other, net
Disaggregation of Revenue [Line Items]
Rental and other property	$ 62,998	68,531	81,604
Apartment communities owned (in communities) | community	2
Rental and other property | Straight line rent concession
Disaggregation of Revenue [Line Items]
Straight line rent concession	$ (21)	(2,543)	(5,558)
Rental and other property | Operating segments | Southern California
Disaggregation of Revenue [Line Items]
Rental and other property	744,004	682,116	646,252
Rental and other property | Operating segments | Northern California
Disaggregation of Revenue [Line Items]
Rental and other property	677,393	642,658	615,677
Rental and other property | Operating segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Rental and other property	295,002	282,092	271,248
Rental and other property | Other real estate assets
Disaggregation of Revenue [Line Items]
Rental and other property	$ 47,786	$ 51,398	$ 62,498