Revenues - Schedule of Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2026 USD ($) community	Sep. 30, 2025 USD ($)	Sep. 30, 2026 USD ($) community	Sep. 30, 2025 USD ($)
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 490,346	$ 470,942	$ 1,459,520	$ 1,400,641
Management and other fees from affiliates	2,344	2,361	6,975	7,078
Total revenues	$ 492,690	473,303	$ 1,466,495	1,407,719
Apartment communities owned (in communities) | community	255		255
Operating Segments | Southern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 195,141	189,262	$ 583,177	564,861
Operating Segments | Northern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	208,638	193,208	615,344	563,915
Operating Segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	79,711	78,683	237,249	233,083
Other real estate assets
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	6,856	9,789	23,750	38,782
Rental income
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	482,770	463,892	1,438,000	1,380,438
Other property
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	7,576	7,050	21,520	20,203
Total rental and other property revenues
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	490,346	470,942	1,459,520	1,400,641
Total rental and other property revenues | Same-property
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 449,896	436,733	$ 1,337,388	1,300,001
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	$ 22,295	13,398	$ 64,551	29,067
Total rental and other property revenues | Non-residential/other, net
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 18,272	20,496	$ 58,016	71,479
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	$ (117)	315	$ (435)	94
Total rental and other property revenues | Operating Segments | Southern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	195,141	189,262	583,177	564,861
Total rental and other property revenues | Operating Segments | Northern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	208,638	193,208	615,344	563,915
Total rental and other property revenues | Operating Segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	79,711	78,683	237,249	233,083
Total rental and other property revenues | Other real estate assets
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 6,856	$ 9,789	$ 23,750	$ 38,782