Organization and Basis of Presentation - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023 USD ($) apartment project partnership community building investment shares	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) investment partnership community shares
Real Estate Properties [Line Items]
Apartment communities owned (in communities) | community	251
Apartment units owned (in apartments) | apartment	61,924
Ownership interest, number of commercial buildings (in commercial buildings) | building	3
Ownership interest, number of unconsolidated joint venture projects (in projects) | project	1
Marketable securities	$ 100		$ 200
Sales and maturities of marketable securities	26,700	$ 27,900
Marketable securities, realized gain (loss)	900	12,200
Unrealized gain (loss) on equity securities recognized through income	$ 368	(24,585)
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	6		6
Assets related to variable interest entities net of intercompany eliminations	$ 945,900		$ 939,400
Liabilities related to variable interest entities net of intercompany eliminations	326,700		324,300
Noncontrolling interest in variable interest entity	121,400		121,500
Fixed rate debt carrying amount	5,700,000		5,700,000
Fixed rate debt fair value	5,300,000		5,200,000
Variable rate debt, carrying amount	222,400		274,200
Variable rate debt fair value	221,600		273,200
Capitalized internal costs related to development and redevelopment projects	4,800	5,400
Redeemable noncontrolling interest	$ 30,208		$ 27,150
Minimum
Real Estate Properties [Line Items]
Apartment lease term	9 months
Maximum
Real Estate Properties [Line Items]
Apartment lease term	12 months
Interest And Other Income (Expense)
Real Estate Properties [Line Items]
Unrealized gain (loss) on equity securities recognized through income	$ 400	(24,600)
Essex Portfolio, L.P.
Real Estate Properties [Line Items]
Operating Partnership units outstanding (in shares) | shares	2,260,842		2,272,496
Redemption value of operating partnership units outstanding	$ 472,800		$ 481,600
Unrealized gain (loss) on equity securities recognized through income	368	$ (24,585)
Redeemable noncontrolling interest	$ 30,208		$ 27,150
Partnership Interest
Real Estate Properties [Line Items]
Ownership interest in partnership	96.60%		96.60%