Condensed Consolidated Statement of Capital - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	$ 85,035	$ 348,381
Reversal of unrealized gains upon the sale of marketable securities		(1,650)
Change in fair value of derivatives and amortization of swap settlements		7,405
Change in fair value of marketable securities, net		1,966
Issuance of common stock under:
Sale of common stock by general partner, net		$ 80,377
Sale of common stock by general partner, net (in units)		311,873
Changes in the redemption value of redeemable noncontrolling interest		$ (903)
Contributions from noncontrolling interest		22,506
Distributions to noncontrolling interest		(21,072)
Redemptions		(28,557)
Essex Portfolio, L.P. [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		6,292,237
Net income	85,035	348,381
Reversal of unrealized gains upon the sale of marketable securities		(1,650)
Change in fair value of derivatives and amortization of swap settlements		7,405
Change in fair value of marketable securities, net		1,966
Issuance of common stock under:
General partner's stock based compensation, net		24,079
Sale of common stock by general partner, net		80,377
Equity based compensation costs		4,894
Changes in the redemption value of redeemable noncontrolling interest		(903)
Contributions from noncontrolling interest		22,506
Distributions to noncontrolling interest		(9,092)
Redemptions		(28,557)
Distributions declared		(357,749)
Balance at period end	6,383,894	6,383,894
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 units)		65,528,000
Net income		$ 329,446
Issuance of common stock under:
General partner's stock based compensation, net		$ 24,079
General partner's stock based compensation, net (in units)		160,000
Sale of common stock by general partner, net		$ 80,377
Sale of common stock by general partner, net (in units)		312,000
Equity based compensation costs		$ 3,814
Changes in the redemption value of redeemable noncontrolling interest		(916)
Redemptions		$ (25,167)
Redemptions (in units)		2,000
Distributions declared		$ (345,769)
Balance at period end	$ 6,290,140	$ 6,290,140
Balance at period end (in units)	66,002,000	66,002,000
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 units)		2,237,000
Net income		$ 11,289
Issuance of common stock under:
Equity based compensation costs		$ 1,080
Equity based compensation costs (in units)		16,000
Changes in the redemption value of redeemable noncontrolling interest		$ 78
Redemptions		$ (405)
Redemptions (in units)		(2,000)
Distributions declared		$ (11,980)
Balance at period end	$ 49,498	$ 49,498
Balance at period end (in units)	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		(1,650)
Change in fair value of derivatives and amortization of swap settlements		7,405
Change in fair value of marketable securities, net		1,966
Issuance of common stock under:
Balance at period end	$ (21,627)	(21,627)
Essex Portfolio, L.P. [Member] | Noncontrolling Interest [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		47,873
Net income		7,646
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		(9,092)
Redemptions		(2,985)
Balance at period end	$ 65,883	$ 65,883