Condensed Consolidated Statement of Capital (Unaudited) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) shares
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	$ 86,907
Change in fair value of derivatives and amortization of swap settlements	(2,528)
Change in fair value of marketable securities	317
Issuance of common stock under:
Sale of common stock by general partner, net	(134)
Changes in the redemption value of redeemable noncontrolling interest	(751)
Distributions to noncontrolling interest	(5,465)
Redemptions	(1,089)
Essex Portfolio, L.P. [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	6,337,023
Net income	86,907
Change in fair value of derivatives and amortization of swap settlements	(2,528)
Change in fair value of marketable securities	317
Issuance of common stock under:
General partner's stock based compensation, net	5,232
Sale of common stock by general partner, net	(134)
Equity based compensation costs	1,490
Reclassification of Series H preferred stock	(73,750)
Changes in the redemption value of redeemable noncontrolling interest	(751)
Distributions to noncontrolling interest	(1,818)
Redemptions	(1,089)
Distributions declared	(109,659)
Balance at period end	6,241,240
Essex Portfolio, L.P. [Member] | Common Equity [Member] | General Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	$ 6,208,535
Balance at period beginning (in shares) | shares	65,379
Net income	$ 77,981
Issuance of common stock under:
General partner's stock based compensation, net	$ 5,232
General partner's stock based compensation (in shares) | shares	41
Sale of common stock by general partner, net	$ (134)
Equity based compensation costs	895
Changes in the redemption value of redeemable noncontrolling interest	(841)
Redemptions	$ (829)
Redemptions (in shares) | shares	7
Distributions declared	$ (104,698)
Balance at period end	$ 6,186,141
Balance at period end (in shares) | shares	65,427
Essex Portfolio, L.P. [Member] | Common Equity [Member] | Limited Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	$ 47,235
Balance at period beginning (in shares) | shares	2,215
Net income	$ 2,784
Issuance of common stock under:
Equity based compensation costs	$ 595
Equity based compensation costs (in shares) | shares	18
Redemptions	$ (78)
Redemptions (in shares) | shares	8
Distributions declared	$ (3,647)
Balance at period end	$ 46,889
Balance at period end (in shares) | shares	2,225
Essex Portfolio, L.P. [Member] | Preferred Equity [Member] | General Partner [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
Essex Portfolio, L.P. [Member] | AOCI Attributable to Parent [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	(2,528)
Change in fair value of marketable securities	317
Issuance of common stock under:
Balance at period end	(41,809)
Essex Portfolio, L.P. [Member] | Noncontrolling Interest [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	49,642
Net income	2,287
Issuance of common stock under:
Changes in the redemption value of redeemable noncontrolling interest	90
Distributions to noncontrolling interest	(1,818)
Redemptions	(182)
Balance at period end	$ 50,019