Revenues - Disaggregation of Revenue (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) community	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Disaggregation of Revenue [Line Items]
Rental and other property	$ 1,658,264	$ 1,595,675	$ 1,431,418
Management and other fees from affiliates	11,131	11,139	9,138
Total revenues	$ 1,669,395	1,606,814	1,440,556
Apartment communities owned (in communities) | community	252
Rental income
Disaggregation of Revenue [Line Items]
Rental and other property	$ 1,636,070	1,573,368	1,410,197
Other property
Disaggregation of Revenue [Line Items]
Rental and other property	22,194	22,307	21,221
Rental and other property
Disaggregation of Revenue [Line Items]
Rental and other property	1,658,264	1,595,675	1,431,418
Rental and other property | Same-property
Disaggregation of Revenue [Line Items]
Rental and other property	$ 1,581,890	1,515,505	1,364,379
Occupancy threshold for classification as stabilized	90.00%
Rental and other property | Acquisitions
Disaggregation of Revenue [Line Items]
Rental and other property	$ 5,449	1,561	0
Rental and other property | Development
Disaggregation of Revenue [Line Items]
Rental and other property	22,883	20,425	15,807
Rental and other property | Redevelopment
Disaggregation of Revenue [Line Items]
Rental and other property	6,232	5,766	6,170
Rental and other property | Non-residential/other, net
Disaggregation of Revenue [Line Items]
Rental and other property	$ 44,353	57,976	56,377
Apartment communities owned (in communities) | community	2
Rental and other property | Straight line rent concession
Disaggregation of Revenue [Line Items]
Straight line rent concession	$ (2,543)	(5,558)	(11,315)
Rental and other property | Operating segments | Southern California
Disaggregation of Revenue [Line Items]
Rental and other property	682,116	646,252	574,129
Rental and other property | Operating segments | Northern California
Disaggregation of Revenue [Line Items]
Rental and other property	666,836	639,306	584,034
Rental and other property | Operating segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Rental and other property	282,092	271,248	239,839
Rental and other property | Other real estate assets
Disaggregation of Revenue [Line Items]
Rental and other property	$ 27,220	$ 38,869	$ 33,416