Condensed Consolidated Statement of Capital - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	$ 75,795	$ 263,346
Reversal of unrealized gains upon the sale of marketable securities		(1,618)
Change in fair value of derivatives and amortization of swap settlements		4,817
Change in fair value of marketable securities, net		687
Issuance of common stock under:
Sale of common stock by general partner, net	$ 80,600	80,565
Sale of common stock by general partner, net (in shares)	311,873
Changes in the redemption value of redeemable noncontrolling interest		(1,117)
Contributions from noncontrolling interest		22,506
Distributions to noncontrolling interest		(15,017)
Redemptions		(3,528)
Essex Portfolio, L.P. [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		6,292,237
Net income	$ 75,795	263,346
Reversal of unrealized gains upon the sale of marketable securities		(1,618)
Change in fair value of derivatives and amortization of swap settlements		4,817
Change in fair value of marketable securities, net		687
Issuance of common stock under:
General partner's stock based compensation, net		22,041
Sale of common stock by general partner, net		80,565
Equity based compensation costs		3,361
Changes in the redemption value of redeemable noncontrolling interest		(1,117)
Contributions from noncontrolling interest		22,506
Distributions to noncontrolling interest		(7,030)
Redemptions		(3,528)
Distributions declared		(238,240)
Balance at period end	6,438,027	6,438,027
Essex Portfolio, L.P. [Member] | Common Equity [Member] | General Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		$ 6,224,276
Balance at period beginning (in shares)		65,528,000
Net income		$ 249,723
Issuance of common stock under:
General partner's stock based compensation, net		$ 22,041
General partner's stock based compensation, net (in shares)		147,000
Sale of common stock by general partner, net		$ 80,565
Sale of common stock by general partner, net (in shares)		312,000
Equity based compensation costs		$ 2,740
Changes in the redemption value of redeemable noncontrolling interest		(1,052)
Redemptions		$ (2,926)
Redemptions (in shares)		2,000
Distributions declared		$ (230,253)
Balance at period end	$ 6,345,114	$ 6,345,114
Balance at period end (in shares)	65,989,000	65,989,000
Essex Portfolio, L.P. [Member] | Common Equity [Member] | Limited Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		$ 49,436
Balance at period beginning (in shares)		2,237,000
Net income		$ 8,568
Issuance of common stock under:
Equity based compensation costs		$ 621
Equity based compensation costs (in shares)		16,000
Redemptions		$ (405)
Redemptions (in shares)		(2,000)
Distributions declared		$ (7,987)
Balance at period end	$ 50,233	$ 50,233
Balance at period end (in shares)	2,251,000	2,251,000
Essex Portfolio, L.P. [Member] | Accumulated Other Comprehensive Loss [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		$ (29,348)
Reversal of unrealized gains upon the sale of marketable securities		(1,618)
Change in fair value of derivatives and amortization of swap settlements		4,817
Change in fair value of marketable securities, net		687
Issuance of common stock under:
Balance at period end	$ (25,462)	(25,462)
Essex Portfolio, L.P. [Member] | Noncontrolling Interest [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		47,873
Net income		5,055
Issuance of common stock under:
Changes in the redemption value of redeemable noncontrolling interest		(65)
Contributions from noncontrolling interest		22,506
Distributions to noncontrolling interest		(7,030)
Redemptions		(197)
Balance at period end	$ 68,142	$ 68,142