Condensed Consolidated Statement of Capital - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020	Jan. 01, 2019
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	$ 328,765	$ 125,505
Reversal of unrealized gains upon the sale of marketable debt securities		33
Change in fair value of derivatives and amortization of swap settlements	(8,782)	(1,993)
Change in fair value of marketable debt securities, net	(305)	123
Issuance of common stock under:
Sale of common stock by general partner, net	(70)	(20)
Retirement of common units, net	(176,311)	(56,989)
Changes in the redemption value of redeemable noncontrolling interest	4,767	(1,767)
Changes in noncontrolling interest from acquisition	1,349
Distributions to noncontrolling interest	(7,879)	(7,164)
Redemptions	(1,368)	(12,213)
ASU 2016-13
Issuance of common stock under:
Cumulative effect adjustment			$ (190)
ASU 2017-12
Issuance of common stock under:
Cumulative effect adjustment				$ 181
Essex Portfolio, L.P.
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	6,403,504	6,393,844
Net income	328,765	125,505
Reversal of unrealized gains upon the sale of marketable debt securities		33
Change in fair value of derivatives and amortization of swap settlements	(8,782)	(1,993)
Change in fair value of marketable debt securities, net	(305)	123
Issuance of common stock under:
General partner's stock based compensation, net	8,665	3,204
Sale of common stock by general partner, net	(70)	(20)
Equity based compensation costs	1,698	2,600
Retirement of common units, net	(176,311)	(56,989)
Changes in the redemption value of redeemable noncontrolling interest	4,767	(1,767)
Changes in noncontrolling interest from acquisition	1,349
Distributions to noncontrolling interest	(3,107)	(2,667)
Redemptions	(1,368)	(12,213)
Distributions declared	(140,666)	(132,646)
Balance at period end	6,417,949	6,317,195
Essex Portfolio, L.P. | ASU 2016-13
Issuance of common stock under:
Cumulative effect adjustment			(190)
Essex Portfolio, L.P. | ASU 2017-12
Issuance of common stock under:
Cumulative effect adjustment		181
Essex Portfolio, L.P. | Common Equity | ASU 2016-13
Issuance of common stock under:
Cumulative effect adjustment			(190)
Essex Portfolio, L.P. | Common Equity | General Partner
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	$ 6,234,315	$ 6,280,290
Balance at period beginning (in shares)	66,092	65,890
Net income	$ 315,006	$ 118,858
Issuance of common stock under:
General partner's stock based compensation, net	$ 8,665	$ 3,204
General partner's stock based compensation, net (in shares)	89	51
Sale of common stock by general partner, net	$ (70)	$ (20)
Sale of common stock by general partner, net (in shares)	0
Equity based compensation costs	$ 1,619	2,301
Retirement of common units, net	$ (176,311)	$ (56,989)
Retirement of common units, net (in shares)	(776)	(234)
Changes in the redemption value of redeemable noncontrolling interest	$ 4,741	$ (3,027)
Redemptions	$ (1,048)	$ (10,394)
Redemptions (in shares)	(7)	(9)
Distributions declared	$ (135,894)	$ (128,149)
Balance at period end	$ 6,250,833	$ 6,206,074
Balance at period end (in shares)	65,412	65,716
Essex Portfolio, L.P. | Common Equity | Limited Partners
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	$ 57,359	$ 59,061
Balance at period beginning (in shares)	2,302	2,305
Net income	$ 10,986	$ 4,171
Issuance of common stock under:
Equity based compensation costs	$ 79	$ 299
Equity based compensation costs (in shares)	2	3
Changes in the redemption value of redeemable noncontrolling interest	$ (18)	$ (2)
Redemptions	$ (84)	$ (365)
Redemptions (in shares)	(8)	(9)
Distributions declared	$ (4,772)	$ (4,497)
Balance at period end	$ 63,550	$ 58,667
Balance at period end (in shares)	2,296	2,299
Essex Portfolio, L.P. | Accumulated Other Comprehensive Loss
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	$ (10,432)	$ (9,738)
Reversal of unrealized gains upon the sale of marketable debt securities		33
Change in fair value of derivatives and amortization of swap settlements	(8,782)	(1,993)
Change in fair value of marketable debt securities, net	(305)	123
Issuance of common stock under:
Balance at period end	(19,519)	(11,394)
Essex Portfolio, L.P. | Accumulated Other Comprehensive Loss | ASU 2016-13
Issuance of common stock under:
Cumulative effect adjustment			$ 0
Essex Portfolio, L.P. | Accumulated Other Comprehensive Loss | ASU 2017-12
Issuance of common stock under:
Cumulative effect adjustment		181
Essex Portfolio, L.P. | Noncontrolling Interest
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	122,262	64,231
Net income	2,773	2,476
Issuance of common stock under:
Changes in the redemption value of redeemable noncontrolling interest	44	1,262
Changes in noncontrolling interest from acquisition	1,349
Distributions to noncontrolling interest	(3,107)	(2,667)
Redemptions	(236)	(1,454)
Balance at period end	$ 123,085	$ 63,848