Quarterly Results of Operations (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Total property revenues	$ 155,986	$ 152,177	$ 148,783	$ 145,057	$ 140,294	$ 133,760	$ 128,465	$ 124,177	$ 602,003	$ 526,696	$ 460,660
Income before discontinued operations	20,020	62,718	28,983	29,161	49,158	19,731	42,050	16,714	140,882	127,653	46,958
Net income	36,903	75,875	29,575	29,702	49,640	20,221	42,490	27,239	172,055	139,590	57,516
Net income available to common stockholders	31,874	68,788	24,946	25,203	43,793	16,219	37,078	22,722	150,811	119,812	40,368
Net income:
Basic (in dollars per share)	$ 0.85	$ 1.84	$ 0.67	$ 0.68	$ 1.22	$ 0.46	$ 1.07	$ 0.67	$ 4.05	$ 3.42	$ 1.24
Diluted (in dollars per share)	$ 0.85	$ 1.84	$ 0.67	$ 0.68	$ 1.22	$ 0.45	$ 1.07	$ 0.67	$ 4.04	$ 3.41	$ 1.24
Market price:
High (in dollars per share)	$ 165.44	$ 172.16	$ 171.11	$ 156.36	$ 150.71	$ 160.64	$ 161.53	$ 151.54
Low (in dollars per share)	$ 137.53	$ 139.64	$ 147.56	$ 147.06	$ 136.38	$ 147.38	$ 146.05	$ 136.43
Close (in dollars per share)	$ 143.51	$ 147.70	$ 158.92	$ 150.58	$ 146.65	$ 148.24	$ 153.92	$ 151.51
Dividends declared (in dollars per share)	$ 1.21	$ 1.21	$ 1.21	$ 1.21	$ 1.10	$ 1.10	$ 1.10	$ 1.10
Essex Portfolio, L.P. [Member]
Total property revenues	155,986	152,177	148,783	145,057	140,294	133,760	128,465	124,177	602,003	526,696	460,660
Income before discontinued operations	20,020	62,718	28,983	29,161	49,158	19,731	42,050	16,714	140,882	127,653	46,958
Net income	36,903	75,875	29,575	29,702	49,640	20,221	42,490	27,239	172,055	139,590	57,516
Net income available to common stockholders	$ 33,776	$ 72,777	$ 26,493	$ 26,703	$ 46,581	$ 17,296	$ 39,580	$ 24,314	$ 159,749	$ 127,771	$ 43,593
Net income:
Basic (in dollars per share)	$ 0.87	$ 1.84	$ 0.67	$ 0.68	$ 1.23	$ 0.46	$ 1.08	$ 0.67	$ 4.06	$ 3.43	$ 1.25
Diluted (in dollars per share)	$ 0.86	$ 1.84	$ 0.67	$ 0.68	$ 1.23	$ 0.45	$ 1.07	$ 0.67	$ 4.05	$ 3.42	$ 1.25
Market price:
Dividends declared (in dollars per share)	$ 1.21	$ 1.21	$ 1.21	$ 1.21	$ 1.10	$ 1.10	$ 1.10	$ 1.10