Condensed Consolidated Statement of Capital - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	$ 70,162	$ 233,893
Change in fair value of derivatives and amortization of swap settlements		3,481
Change in fair value of marketable securities, net		(1,500)
Issuance of common stock under:
Sale of common stock by general partner, net		(382)
Changes in the redemption value of redeemable noncontrolling interest		1,343
Distributions to noncontrolling interest		(20,425)
Redemptions		(2,435)
Essex Portfolio, L.P. [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		6,337,023
Net income	70,162	233,893
Change in fair value of derivatives and amortization of swap settlements		3,481
Change in fair value of marketable securities, net		(1,500)
Issuance of common stock under:
General partner's stock based compensation, net		17,878
Sale of common stock by general partner, net		(382)
Equity based compensation costs		4,436
Reclassification of Series H preferred stock		(73,750)
Changes in the redemption value of redeemable noncontrolling interest		1,343
Distributions to noncontrolling interest		(9,502)
Redemptions		(2,435)
Distributions declared		(326,583)
Balance at period end	6,183,902	6,183,902
Essex Portfolio, L.P. [Member] | Accumulated Other Comprehensive Loss, Net [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		(39,598)
Change in fair value of derivatives and amortization of swap settlements		3,481
Change in fair value of marketable securities, net		(1,500)
Issuance of common stock under:
Balance at period end	(37,617)	(37,617)
Essex Portfolio, L.P. [Member] | Noncontrolling Interest [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		49,642
Net income		7,026
Issuance of common stock under:
Changes in the redemption value of redeemable noncontrolling interest		558
Distributions to noncontrolling interest		(9,502)
Redemptions		(411)
Balance at period end	47,313	47,313
Essex Portfolio, L.P. [Member] | General Partner [Member] | Common Equity [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		$ 6,208,535
Balance at period beginning (in shares)		65,379
Net income		$ 215,555
Issuance of common stock under:
General partner's stock based compensation, net		$ 17,878
General partner's stock based compensation, net (in shares)		130
Sale of common stock by general partner, net		$ (382)
Equity based compensation costs		2,662
Changes in the redemption value of redeemable noncontrolling interest		785
Redemptions		$ (1,974)
Redemptions (in shares)		14
Distributions declared		$ (314,346)
Balance at period end	$ 6,128,713	$ 6,128,713
Balance at period end (in shares)	65,523	65,523
Essex Portfolio, L.P. [Member] | General Partner [Member] | Preferred Equity [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		$ 71,209
Net income		3,855
Issuance of common stock under:
Reclassification of Series H preferred stock		(73,750)
Distributions declared		(1,314)
Balance at period end	$ 0	0
Essex Portfolio, L.P. [Member] | Limited Partner [Member] | Common Equity [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		$ 47,235
Balance at period beginning (in shares)		2,215
Net income		$ 7,457
Issuance of common stock under:
Equity based compensation costs		$ 1,774
Equity based compensation costs (in shares)		18
Redemptions		$ (50)
Redemptions (in shares)		(14)
Distributions declared		$ (10,923)
Balance at period end	$ 45,493	$ 45,493
Balance at period end (in shares)	2,219	2,219