Unsecured Debt - Narrative (Details)	1 Months Ended			3 Months Ended	12 Months Ended
	May 31, 2024 USD ($)	Jun. 30, 2020 USD ($)	Apr. 30, 2013 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2024 USD ($) extension_option	Dec. 31, 2024 USD ($) instrument	Dec. 31, 2024 USD ($) line_of_credit	Aug. 31, 2024 USD ($)	Jul. 01, 2024 USD ($)	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Aug. 31, 2020 USD ($)	Feb. 29, 2020 USD ($)	Oct. 31, 2019 USD ($)	Aug. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)	Feb. 28, 2019 USD ($)	Mar. 31, 2018 USD ($)	Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)	Mar. 31, 2015 USD ($)	Apr. 30, 2014 USD ($)
Debt Instrument [Line Items]
Debt instrument face amount					$ 5,200,000,000	$ 5,200,000,000	$ 5,200,000,000	$ 5,200,000,000	$ 5,200,000,000					$ 5,050,000,000
Unsecured debt, net					5,473,788,000	5,473,788,000	5,473,788,000	$ 5,473,788,000	$ 5,473,788,000					5,318,531,000
Number of lines of credit								2	2
Lines of credit					137,945,000	137,945,000	137,945,000	$ 137,945,000	$ 137,945,000					0
Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity											$ 75,000,000	$ 35,000,000
CPPIB Interest
Debt Instrument [Line Items]
Investment interest acquired				45.00%
Essex Portfolio, L.P.
Debt Instrument [Line Items]
Unsecured debt, net					5,473,788,000	5,473,788,000	5,473,788,000	5,473,788,000	5,473,788,000					5,318,531,000
Lines of credit					137,945,000	137,945,000	137,945,000	137,945,000	137,945,000					0
Fixed Rate Bond
Debt Instrument [Line Items]
Unamortized debt issuance expense					549,800,000	549,800,000	549,800,000	549,800,000	549,800,000					0
Senior Notes
Debt Instrument [Line Items]
Debt instrument, repaid, principal	$ 400,000,000
Senior Notes | Essex Portfolio, L.P.
Debt Instrument [Line Items]
Debt instrument face amount																	$ 600,000,000
Line of Credit
Debt Instrument [Line Items]
Debt instrument face amount					1,280,000,000	1,280,000,000	1,280,000,000	1,280,000,000	1,280,000,000					1,280,000,000
Unamortized debt issuance expense					6,200,000	6,200,000	6,200,000	6,200,000	6,200,000					3,800,000
Maximum borrowing capacity					1,200,000,000	1,200,000,000	1,200,000,000	1,200,000,000	1,200,000,000
Lines of credit					$ 137,945,000	$ 137,945,000	$ 137,945,000	137,945,000	137,945,000					0
Number of extension options | extension_option							2
Extension period					6 months
Basis spread on rate						0.765%
Line of Credit | Line of Credit Working Capital
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 75,000,000.0	$ 75,000,000.0	$ 75,000,000.0	75,000,000.0	75,000,000.0
Unsecured Line of Credit
Debt Instrument [Line Items]
Number of extension options | extension_option							2
Extension period					6 months
Basis spread on rate						0.765%
Unsecured Line of Credit | Line of Credit Working Capital
Debt Instrument [Line Items]
Lines of credit					$ 62,900,000	$ 62,900,000	$ 62,900,000	62,900,000	62,900,000					0
Unsecured Bonds 5.500%, Due March 2028 | Fixed Rate Bond | Essex Portfolio, L.P.
Debt Instrument [Line Items]
Debt instrument face amount													$ 350,000,000
Coupon rate													5.50%
Debt instrument, debt offering price, percentage of principal													99.752%
Unsecured Bonds 5.500%
Debt Instrument [Line Items]
Debt instrument face amount					$ 550,000,000	$ 550,000,000	$ 550,000,000	$ 550,000,000	$ 550,000,000					0
Unsecured Bonds 5.500% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount										$ 200,000,000
Coupon rate					5.50%	5.50%	5.50%	5.50%	5.50%
Debt instrument, debt offering price, percentage of principal amount										102.871%
Debt instrument, debt offering price, effective yield percentage										5.11%
Unsecured Bonds 2.550%
Debt Instrument [Line Items]
Debt instrument face amount					$ 300,000,000	$ 300,000,000	$ 300,000,000	$ 300,000,000	$ 300,000,000					300,000,000
Unsecured Bonds 2.550% | Senior Notes
Debt Instrument [Line Items]
Coupon rate					2.55%	2.55%	2.55%	2.55%	2.55%
Unsecured debt, net					$ 297,100,000	$ 297,100,000	$ 297,100,000	$ 297,100,000	$ 297,100,000					296,700,000
Unsecured Bonds 2.550% | Senior Notes | Essex Portfolio, L.P.
Debt Instrument [Line Items]
Debt instrument face amount															$ 300,000,000
Coupon rate															2.55%
Debt offering price															99.367%
Unsecured Bonds 3.375% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount															$ 300,000,000
Coupon rate															3.375%
Unsecured Bonds 1.700%
Debt Instrument [Line Items]
Debt instrument face amount					$ 450,000,000	$ 450,000,000	$ 450,000,000	$ 450,000,000	$ 450,000,000					450,000,000
Unsecured Bonds 1.700% | Senior Notes
Debt Instrument [Line Items]
Coupon rate					1.70%	1.70%	1.70%	1.70%	1.70%
Unsecured debt, net					$ 447,200,000	$ 447,200,000	$ 447,200,000	$ 447,200,000	$ 447,200,000					446,300,000
Unsecured Bonds 1.700% | Senior Notes | Essex Portfolio, L.P.
Debt Instrument [Line Items]
Debt instrument face amount																$ 450,000,000
Coupon rate																1.70%
Debt offering price																99.423%
Unsecured Bonds 2.650%
Debt Instrument [Line Items]
Debt instrument face amount					$ 650,000,000	$ 650,000,000	$ 650,000,000	$ 650,000,000	$ 650,000,000					650,000,000
Unsecured Bonds 2.650% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount		$ 150,000,000
Coupon rate					2.65%	2.65%	2.65%	2.65%	2.65%
Debt offering price		105.66%
Unsecured debt, net					$ 650,600,000	$ 650,600,000	$ 650,600,000	$ 650,600,000	$ 650,600,000					650,700,000
Reoffer yield percentage		2.093%
Unsecured Bonds 2.650% | Senior Notes | Essex Portfolio, L.P.
Debt Instrument [Line Items]
Debt instrument face amount																		$ 500,000,000
Coupon rate																		2.65%
Debt offering price																		99.628%
Repayments of secured debt				$ 100,300,000
Unsecured Bonds 1.650%
Debt Instrument [Line Items]
Debt instrument face amount					$ 300,000,000	$ 300,000,000	$ 300,000,000	$ 300,000,000	$ 300,000,000					300,000,000
Unsecured Bonds 1.650% | Senior Notes
Debt Instrument [Line Items]
Coupon rate					1.65%	1.65%	1.65%	1.65%	1.65%
Debt offering price																	99.035%
Unsecured Bonds 1.650% | Senior Notes | Essex Portfolio, L.P.
Debt Instrument [Line Items]
Debt instrument face amount																	$ 300,000,000
Coupon rate																	1.65%
Unsecured debt, net					$ 296,700,000	$ 296,700,000	$ 296,700,000	$ 296,700,000	$ 296,700,000					296,100,000
Unsecured Bonds 2.650%
Debt Instrument [Line Items]
Debt instrument face amount					$ 300,000,000	$ 300,000,000	$ 300,000,000	$ 300,000,000	$ 300,000,000					300,000,000
Unsecured Bonds 2.650% | Senior Notes
Debt Instrument [Line Items]
Coupon rate					2.65%	2.65%	2.65%	2.65%	2.65%
Debt offering price																	99.691%
Unsecured Bonds 2.650% | Senior Notes | Essex Portfolio, L.P.
Debt Instrument [Line Items]
Debt instrument face amount																	$ 300,000,000
Coupon rate																	2.65%
Unsecured debt, net					$ 296,100,000	$ 296,100,000	$ 296,100,000	$ 296,100,000	$ 296,100,000					296,000,000
Unsecured Bonds 3.625% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount																	$ 300,000,000
Coupon rate																	3.625%
Unsecured Bonds 3.000%
Debt Instrument [Line Items]
Debt instrument face amount					$ 550,000,000	$ 550,000,000	$ 550,000,000	$ 550,000,000	$ 550,000,000					550,000,000
Unsecured Bonds 3.000% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount																			$ 150,000,000.0	$ 400,000,000.0
Coupon rate					3.00%	3.00%	3.00%	3.00%	3.00%											3.00%
Debt offering price																			101.685%	98.632%
Unsecured debt, net					$ 546,200,000	$ 546,200,000	$ 546,200,000	$ 546,200,000	$ 546,200,000					545,500,000
Unsecured Bonds 4.000%
Debt Instrument [Line Items]
Debt instrument face amount					$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000					500,000,000
Unsecured Bonds 4.000% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount																					$ 150,000,000.0	$ 350,000,000.0
Coupon rate					4.00%	4.00%	4.00%	4.00%	4.00%													4.00%
Debt offering price																					100.717%	99.188%
Unsecured debt, net					$ 497,300,000	$ 497,300,000	$ 497,300,000	$ 497,300,000	$ 497,300,000					496,700,000
Unsecured Bonds 4.500%
Debt Instrument [Line Items]
Debt instrument face amount					$ 300,000,000	$ 300,000,000	$ 300,000,000	$ 300,000,000	$ 300,000,000					300,000,000
Unsecured Bonds 4.500% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount																							$ 300,000,000.0
Coupon rate					4.50%	4.50%	4.50%	4.50%	4.50%														4.50%
Debt offering price																							99.591%
Unsecured debt, net					$ 296,400,000	$ 296,400,000	$ 296,400,000	$ 296,400,000	$ 296,400,000					296,200,000
Unsecured Bonds 3.625%
Debt Instrument [Line Items]
Debt instrument face amount					$ 350,000,000	$ 350,000,000	$ 350,000,000	$ 350,000,000	$ 350,000,000					350,000,000
Unsecured Bonds 3.625% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount																								$ 350,000,000.0
Coupon rate					3.625%	3.625%	3.625%	3.625%	3.625%															3.625%
Debt offering price																								99.423%
Unsecured debt, net					$ 348,800,000	$ 348,800,000	$ 348,800,000	$ 348,800,000	$ 348,800,000					348,300,000
Unsecured Bonds 3.375%, Due April 2026
Debt Instrument [Line Items]
Debt instrument face amount					$ 450,000,000	$ 450,000,000	$ 450,000,000	$ 450,000,000	$ 450,000,000					450,000,000
Unsecured Bonds 3.375%, Due April 2026 | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount																									$ 450,000,000.0
Coupon rate					3.375%	3.375%	3.375%	3.375%	3.375%																3.375%
Debt offering price																									99.386%
Unsecured debt, net					$ 449,100,000	$ 449,100,000	$ 449,100,000	$ 449,100,000	$ 449,100,000					448,400,000
Senior Unsecured Notes Maturing April 1, 2025 | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount																										$ 500,000,000.0
Coupon rate																										3.50%
Debt offering price																										99.747%
Unsecured debt, net					499,900,000	499,900,000	499,900,000	499,900,000	499,900,000					499,300,000
Unsecured Bonds 3.875%
Debt Instrument [Line Items]
Debt instrument face amount					$ 0	$ 0	$ 0	$ 0	$ 0					400,000,000
Unsecured Bonds 3.875% | Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount																											$ 400,000,000.0
Coupon rate					3.875%	3.875%	3.875%	3.875%	3.875%																		3.875%
Debt offering price																											99.234%
Unsecured debt, net					$ 0	$ 0	$ 0	$ 0	$ 0					399,800,000
Unsecured Bonds 3.250% | Senior Notes
Debt Instrument [Line Items]
Coupon rate			3.25%
Debt offering price			99.152%
Proceeds from issuance of unsecured debt			$ 300,000,000.0
Unsecured Line of Credit | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity					1,200,000,000	1,200,000,000	1,200,000,000	1,200,000,000	1,200,000,000
Lines of credit					$ 75,000,000.0	$ 75,000,000.0	$ 75,000,000.0	$ 75,000,000.0	$ 75,000,000.0					$ 0