Revenues - Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) community	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Rental and other property	$ 409,656	$ 379,216
Management and other fees from affiliates	2,765	2,689
Revenues	$ 412,421	381,905
Apartment communities owned (in communities) | community	251
Deferred revenue	$ 1,500		$ 1,700
Deferred revenue, revenue recognized	200
Deferred revenue balance from contracts with remaining performance obligations	1,500
Rental income
Disaggregation of Revenue [Line Items]
Rental and other property	404,635	373,425
Other property
Disaggregation of Revenue [Line Items]
Rental and other property	5,021	5,791
Rental and other property revenues
Disaggregation of Revenue [Line Items]
Rental and other property	409,656	379,216
Rental and other property revenues | Same-property
Disaggregation of Revenue [Line Items]
Rental and other property	$ 388,895	361,415
Occupancy threshold for classification as stabilized	90.00%
Rental and other property revenues | Acquisitions
Disaggregation of Revenue [Line Items]
Rental and other property	$ 1,021	0
Rental and other property revenues | Development
Disaggregation of Revenue [Line Items]
Rental and other property	5,500	4,227
Rental and other property revenues | Redevelopment
Disaggregation of Revenue [Line Items]
Rental and other property	1,537	1,435
Rental and other property revenues | Non-residential/other, net
Disaggregation of Revenue [Line Items]
Rental and other property	$ 12,127	15,023
Apartment communities owned (in communities) | community	2
Rental and other property revenues | Straight line rent concession
Disaggregation of Revenue [Line Items]
Rental and other property	$ 576	(2,884)
Rental and other property revenues | Operating Segments | Southern California
Disaggregation of Revenue [Line Items]
Rental and other property	166,877	153,339
Rental and other property revenues | Operating Segments | Northern California
Disaggregation of Revenue [Line Items]
Rental and other property	163,624	152,745
Rental and other property revenues | Operating Segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Rental and other property	70,038	64,203
Rental and other property revenues | Other real estate assets
Disaggregation of Revenue [Line Items]
Rental and other property	$ 9,117	$ 8,929