Revenues - Schedule of Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026 USD ($) community	Jun. 30, 2025 USD ($)	Jun. 30, 2026 USD ($) community	Jun. 30, 2025 USD ($)
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 486,731	$ 467,610	$ 969,174	$ 929,699
Management and other fees from affiliates	2,318	2,223	4,631	4,717
Total revenues	$ 489,049	469,833	$ 973,805	934,416
Apartment communities owned (in communities) | community	258		258
Operating Segments | Southern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 195,506	189,744	$ 390,811	378,366
Operating Segments | Northern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	205,088	189,791	406,706	370,707
Operating Segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	79,633	78,297	158,654	155,511
Other real estate assets
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	6,504	9,778	13,003	25,115
Rental income
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	479,418	460,686	955,230	916,546
Other property
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	7,313	6,924	13,944	13,153
Total rental and other property revenues
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	486,731	467,610	969,174	929,699
Total rental and other property revenues | Same-property
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 446,035	434,370	$ 888,607	864,379
Occupancy threshold for classification as stabilized (in percent)	90.00%		90.00%
Total rental and other property revenues | Acquisitions
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 21,495	11,099	$ 42,256	15,669
Total rental and other property revenues | Non-residential/other, net
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 19,404	21,974	$ 38,629	49,872
Apartment communities owned (in communities) | community	2		2
Total rental and other property revenues | Straight line rent concession
Disaggregation of Revenue [Line Items]
Straight line rent concession	$ (203)	167	$ (318)	(221)
Total rental and other property revenues | Operating Segments | Southern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	195,506	189,744	390,811	378,366
Total rental and other property revenues | Operating Segments | Northern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	205,088	189,791	406,706	370,707
Total rental and other property revenues | Operating Segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	79,633	78,297	158,654	155,511
Total rental and other property revenues | Other real estate assets
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 6,504	$ 9,778	$ 13,003	$ 25,115