Segment Information - Schedule of Reconciliation of Revenues and Operating Profit (Loss) from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
Rental and Other Property Revenue	$ 490,346	$ 470,942	$ 1,459,520	$ 1,400,641
Property Operating Expenses, Including Real Estate Taxes	149,496	143,436	431,774	417,486
Net Operating Income	340,850	327,506	1,027,746	983,155
Management and other fees from affiliates	2,344	2,361	6,975	7,078
Corporate-level property management expenses	(13,393)	(12,216)	(40,223)	(36,768)
Depreciation and amortization	(152,552)	(151,489)	(461,520)	(454,277)
General and administrative	(16,561)	(18,058)	(109,724)	(51,507)
Expensed acquisition and investment related costs	0	(25)	0	(25)
Impairment loss	(10,709)	0	(10,709)	0
Gain on sale of real estate and land	6,781	62,320	8,781	299,524
Interest expense	(64,755)	(64,660)	(197,155)	(192,654)
Total return swap income	1,339	1,329	4,108	3,600
Interest and other income	686	5,900	10,809	16,997
Equity income from co-investments	9,212	17,798	46,542	39,984
Tax benefit on unconsolidated technology co-investments	493	1,958	(2,758)	2,353
Loss on early retirement of debt	0	0	0	(762)
Gain on remeasurement of co-investment	0	0	0	330
Net income (loss)	103,735	172,724	282,872	617,028
Operating Segments | Southern California
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
Rental and Other Property Revenue	195,141	189,262	583,177	564,861
Property Operating Expenses, Including Real Estate Taxes	60,254	57,019	173,919	164,971
Net Operating Income	134,887	132,243	409,258	399,890
Operating Segments | Northern California
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
Rental and Other Property Revenue	208,638	193,208	615,344	563,915
Property Operating Expenses, Including Real Estate Taxes	64,038	61,158	183,897	175,499
Net Operating Income	144,600	132,050	431,447	388,416
Operating Segments | Seattle Metro
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
Rental and Other Property Revenue	79,711	78,683	237,249	233,083
Property Operating Expenses, Including Real Estate Taxes	24,372	23,141	70,430	67,151
Net Operating Income	55,339	55,542	166,819	165,932
Other real estate assets
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
Rental and Other Property Revenue	6,856	9,789	23,750	38,782
Property Operating Expenses, Including Real Estate Taxes	832	2,118	3,528	9,865
Net Operating Income	$ 6,024	$ 7,671	$ 20,222	$ 28,917