Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	656,020,000	656,020,000
Common stock, shares issued (in shares)	65,042,681	63,682,646
Common stock, shares outstanding (in shares)	65,042,681	63,682,646
Series H Preferred Interest [Member]
Preferred stock, stated interest percentage	7.125%	7.125%
Essex Portfolio, L.P. [Member] | Series H Preferred Interest [Member]
Preferred interest, liquidation value	$ 73,750	$ 73,750
Preferred stock, stated interest percentage	7.125%	7.125%
Essex Portfolio, L.P. [Member] | General Partner [Member]
Common stock, shares issued (in shares)	65,042,681	63,682,646
Common stock, shares outstanding (in shares)	65,042,681	63,682,646
Essex Portfolio, L.P. [Member] | Limited Partners [Member]
Common stock, shares issued (in shares)	2,181,076	2,168,158
Common stock, shares outstanding (in shares)	2,181,076	2,168,158