Organization and Basis of Presentation - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2025 USD ($) partnership community building project investment apartment shares	Mar. 31, 2024 USD ($) lawsuit	Dec. 31, 2024 USD ($) community partnership investment shares
Real Estate Properties [Line Items]
Apartment communities owned (in communities) | community	258
Apartment units owned (in apartments) | apartment	62,772
Ownership interest, number of commercial buildings (in commercial buildings) | building	2
Development pipeline consisting of consolidated project | project	1
Marketable securities (less than)	$ 100		$ 100
DownREIT limited partnerships consolidated by company (in partnerships) | partnership	18		18
Communities within DownREIT partnerships (in communities) | community	9		9
Number of previously consolidated co-investments considered VIE (in investments) | investment	4		5
Assets related to variable interest entities net of intercompany eliminations	$ 818,000		$ 893,000
Liabilities related to variable interest entities net of intercompany eliminations	243,900		319,100
Noncontrolling interest in variable interest entity	101,400		105,100
Fixed rate debt carrying amount	6,200,000		5,800,000
Fixed rate debt fair value	5,900,000		5,500,000
Variable rate debt, carrying amount	614,300		752,300
Variable rate debt fair value	611,900		749,400
Capitalized internal costs related to development and redevelopment projects	6,200	$ 5,300
Redeemable noncontrolling interest	$ 34,376		$ 30,849
Number of company settled lawsuits | lawsuit		2
Construction defects at communities | community	2
Gain contingencies from legal settlements	$ 0	$ 42,500
Minimum
Real Estate Properties [Line Items]
Apartment lease term	9 months
Maximum
Real Estate Properties [Line Items]
Apartment lease term	12 months
Essex Portfolio, L.P.
Real Estate Properties [Line Items]
Operating partnership units outstanding (in shares) | shares	2,283,494		2,331,251
Redemption value of operating partnership units outstanding	$ 700,100		$ 665,400
Redeemable noncontrolling interest	$ 34,376		$ 30,849
Partnership Interest
Real Estate Properties [Line Items]
Ownership interest in partnership	96.60%		96.50%