Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Related party receivables	$ 10.8	$ 41.2
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	670,000,000	670,000,000
Common stock, shares issued (in shares)	66,049,618	66,054,399
Common stock, shares outstanding (in shares)	66,049,618	66,054,399
Essex Portfolio, L.P. [Member]
Related party receivables	$ 10.8	$ 41.2
Essex Portfolio, L.P. [Member] | General Partner [Member]
Common stock, shares issued (in shares)	66,049,618	66,054,399
Common stock, shares outstanding (in shares)	66,049,618	66,054,399
Essex Portfolio, L.P. [Member] | Limited Partners [Member]
Common stock, shares issued (in shares)	2,272,983	2,268,114
Common stock, shares outstanding (in shares)	2,272,983	2,268,114