Revenues - Schedule of Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($) community	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) community	Sep. 30, 2024 USD ($)
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 470,942	$ 448,135	$ 1,400,641	$ 1,312,132
Management and other fees from affiliates	2,361	2,563	7,078	7,849
Total revenues	$ 473,303	450,698	$ 1,407,719	1,319,981
Apartment communities owned (in communities) | community	257		257
Operating Segments | Southern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 190,626	181,673	$ 568,992	530,051
Operating Segments | Northern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	193,208	168,838	563,915	490,824
Operating Segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	79,240	74,576	234,751	220,271
Other real estate assets
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	7,868	23,048	32,983	70,986
Rental income
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	463,892	440,649	1,380,438	1,290,026
Other property
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	7,050	7,486	20,203	22,106
Total rental and other property revenues
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	470,942	448,135	1,400,641	1,312,132
Total rental and other property revenues | Same-property
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 412,710	401,761	$ 1,228,141	1,190,884
Occupancy threshold for classification as stabilized	90.00%		90.00%
Total rental and other property revenues | Acquisitions
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 44,001	16,964	$ 120,555	31,386
Total rental and other property revenues | Non-residential/other, net
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 13,916	29,637	$ 51,851	90,663
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	$ 315	(227)	$ 94	(801)
Total rental and other property revenues | Operating Segments | Southern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	190,626	181,673	568,992	530,051
Total rental and other property revenues | Operating Segments | Northern California
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	193,208	168,838	563,915	490,824
Total rental and other property revenues | Operating Segments | Seattle Metro
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	79,240	74,576	234,751	220,271
Total rental and other property revenues | Other real estate assets
Disaggregation of Revenue [Line Items]
Total rental and other property revenues	$ 7,868	$ 23,048	$ 32,983	$ 70,986