Net Income Per Common Share and Net Income Per Common Unit - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Convertible units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	2,280,379	2,259,236	2,266,054	2,261,832
Income allocated to convertible OP Units	$ 4.2	$ 3.1	$ 17.1	$ 12.0
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	197,474
Stock options | Essex Portfolio, L.P.
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	197,474	461,873	327,048	501,187