Organization and Basis of Presentation - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2026 USD ($) investment project community apartment partnership building shares	Jun. 30, 2025 USD ($)	Jun. 30, 2026 USD ($) investment project community apartment partnership building shares	Jun. 30, 2025 USD ($)	Dec. 31, 2025 USD ($) investment community partnership shares
Real Estate Properties [Line Items]
Apartment communities owned (in communities) | community	258		258
Apartment units owned (in apartments) | apartment	62,881		62,881
Ownership interest, number of commercial buildings (in commercial buildings) | building	2		2
Development pipeline consisting of consolidated project (in project) | project	1		1
Marketable securities (less than)	$ 0		$ 0		$ 100
DownREIT limited partnerships consolidated by company (in partnerships) | partnership	18		18		18
Communities within DownREIT partnerships (in communities) | community	10		10		10
Number of previously consolidated co-investments considered VIE (in investments) | investment	4		4		4
Assets related to variable interest entities net of intercompany eliminations	$ 988,100		$ 988,100		$ 970,600
Liabilities related to variable interest entities net of intercompany eliminations	242,400		242,400		242,500
Noncontrolling interest in variable interest entity	101,200		101,200		101,200
Fixed rate debt carrying amount	5,500,000		5,500,000		5,900,000
Fixed rate debt fair value	5,300,000		5,300,000		5,800,000
Variable rate debt, carrying amount	1,200,000		1,200,000		854,400
Variable rate debt fair value	1,200,000		1,200,000		853,200
Capitalized internal costs related to development and redevelopment projects	6,800	$ 6,100	13,500	$ 12,300
Redeemable noncontrolling interest	$ 27,373		$ 27,373		$ 28,263
Minimum
Real Estate Properties [Line Items]
Apartment lease term (in months)	9 months		9 months
Maximum
Real Estate Properties [Line Items]
Apartment lease term (in months)	12 months		12 months
Essex Portfolio, L.P.
Real Estate Properties [Line Items]
Operating partnership units outstanding (in shares) | shares	2,183,943		2,183,943		2,250,339
Redemption value of operating partnership units outstanding	$ 636,800		$ 636,800		$ 588,900
Redeemable noncontrolling interest	$ 27,373		$ 27,373		$ 28,263
Partnership Interest
Real Estate Properties [Line Items]
Ownership interest in partnership (in percent)			96.70%		96.60%