Condensed Consolidated Statement of Capital - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2017
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	$ 98,061	$ 106,410	$ 223,566	$ 203,049
Reversal of unrealized gains upon the sale of marketable debt securities	(65)	3	(32)	2
Change in fair value of marketable debt securities, net	105	(22)	228	(99)
Issuance of common stock under:
Sale of common stock by general partner, net	(62)	(286)	(82)	(353)
Retirement of common units, net			(56,989)	(3,774)
Changes in the redemption value of redeemable noncontrolling interest	339	108	(1,428)	(1,845)
Changes in noncontrolling interest from acquisition	65,472		65,472
Distributions to noncontrolling interest	(6,944)	(9,100)	(14,108)	(15,397)
Redemptions	(1,966)	(57)	(14,179)	(57)
ASU 2016-01 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					$ 0
ASU 2017-05 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					123,708
Essex Portfolio, L.P. [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	6,317,195	6,492,159	6,393,844	6,396,825
Net income	98,061	106,410	223,566	203,049
Reversal of unrealized gains upon the sale of marketable debt securities	(65)	3	(32)	2
Change in fair value of derivatives and amortization of swap settlements	(4,361)	3,402	(6,354)	9,656
Change in fair value of marketable debt securities, net	105	(22)	228	(99)
Issuance of common stock under:
General partner's stock based compensation, net	2,024	642	5,228	1,864
Sale of common stock by general partner, net	(62)	(286)	(82)	(353)
Equity based compensation costs	3,500	4,284	6,100	6,814
Retirement of common units, net			(56,989)	(3,774)
Changes in the redemption value of redeemable noncontrolling interest	339	108	(1,428)	(1,845)
Changes in noncontrolling interest from acquisition	65,472		65,472
Distributions to noncontrolling interest	(2,443)	(4,846)	(5,110)	(6,890)
Redemptions	(1,966)	(57)	(14,179)	(57)
Distributions declared	(132,683)	(127,114)	(265,329)	(254,217)
Balance at period end	6,345,116	6,474,683	6,345,116	6,474,683
Essex Portfolio, L.P. [Member] | ASU 2016-01 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					0
Essex Portfolio, L.P. [Member] | ASU 2017-05 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					123,708
Essex Portfolio, L.P. [Member] | Common Equity [Member] | General Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	$ 6,206,074	$ 6,383,482	$ 6,280,290	$ 6,295,852
Balance at period beginning (in units)	65,716	66,044	65,890	66,054
Net income	$ 92,275	$ 100,440	$ 211,133	$ 191,358
Issuance of common stock under:
General partner's stock based compensation, net	$ 2,024	$ 642	$ 5,228	$ 1,864
General partner's stock based compensation, net (in units)	11	5	62	12
Sale of common stock by general partner, net	$ (62)	$ (286)	$ (82)	$ (353)
Equity based compensation costs	$ 3,171	3,948	5,472	6,201
Equity based compensation costs (in units)	0
Retirement of common units, net			$ (56,989)	$ (3,774)
Retirement of common units, net (in shares)			(234)	(17)
Changes in the redemption value of redeemable noncontrolling interest	$ 288	311	$ (2,739)	$ (1,646)
Redemptions	$ (1,689)	$ (54)	$ (12,083)	$ (54)
Redemptions (in units)	0	(1)	(9)	(1)
Distributions declared	$ (128,182)	$ (122,860)	$ (256,331)	$ (245,710)
Balance at period end	$ 6,173,899	$ 6,365,623	$ 6,173,899	$ 6,365,623
Balance at period end (in units)	65,727	66,050	65,727	66,050
Essex Portfolio, L.P. [Member] | Common Equity [Member] | General Partner [Member] | ASU 2016-01 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					2,234
Essex Portfolio, L.P. [Member] | Common Equity [Member] | General Partner [Member] | ASU 2017-05 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					119,651
Essex Portfolio, L.P. [Member] | Common Equity [Member] | Limited Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	$ 58,667	$ 53,003	$ 59,061	$ 49,792
Balance at period beginning (in units)	2,299	2,273	2,305	2,268
Net income	$ 3,228	$ 3,460	$ 7,399	$ 6,592
Issuance of common stock under:
Equity based compensation costs	$ 329	$ 336	$ 628	$ 613
Equity based compensation costs (in units)	0	0	3	5
Changes in the redemption value of redeemable noncontrolling interest	$ 4	$ (203)	$ 2	$ (199)
Redemptions	$ (1)	$ (3)	$ (366)	$ (3)
Redemptions (in units)	0	0	(9)	0
Distributions declared	$ (4,501)	$ (4,254)	$ (8,998)	$ (8,507)
Balance at period end	$ 57,726	$ 52,339	$ 57,726	$ 52,339
Balance at period end (in units)	2,299	2,273	2,299	2,273
Essex Portfolio, L.P. [Member] | Common Equity [Member] | Limited Partner [Member] | ASU 2016-01 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					(6)
Essex Portfolio, L.P. [Member] | Common Equity [Member] | Limited Partner [Member] | ASU 2017-05 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					4,057
Essex Portfolio, L.P. [Member] | Accumulated Other Comprehensive Loss [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	$ (11,394)	$ (11,281)	$ (9,738)	$ (15,229)
Reversal of unrealized gains upon the sale of marketable debt securities	(65)	3	(32)	2
Change in fair value of derivatives and amortization of swap settlements	(4,361)	3,402	(6,354)	9,656
Change in fair value of marketable debt securities, net	105	(22)	228	(99)
Issuance of common stock under:
Balance at period end	(15,715)	(7,898)	(15,715)	(7,898)
Essex Portfolio, L.P. [Member] | Accumulated Other Comprehensive Loss [Member] | ASU 2016-01 [Member]
Issuance of common stock under:
Cumulative effect upon adoption of ASU					$ (2,228)
Essex Portfolio, L.P. [Member] | Noncontrolling Interest [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	63,848	66,955	64,231	66,410
Net income	2,558	2,510	5,034	5,099
Issuance of common stock under:
Changes in the redemption value of redeemable noncontrolling interest	47		1,309
Changes in noncontrolling interest from acquisition	65,472		65,472
Distributions to noncontrolling interest	(2,443)	(4,846)	(5,110)	(6,890)
Redemptions	(276)		(1,730)
Balance at period end	$ 129,206	$ 64,619	$ 129,206	$ 64,619