Condensed Consolidated Statement of Capital (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	$ 176,949	$ 328,765
Change in fair value of derivatives and amortization of swap settlements	4,407	(8,782)
Change in fair value of marketable debt securities, net	85	(305)
Issuance of common stock under:
Sale of common stock by general partner, net		(70)
Retirement of common units, net	(9,172)	$ (176,311)
Accounting standards update		us-gaap:AccountingStandardsUpdate201613Member
Changes in the redemption value of redeemable noncontrolling interest	(4,083)	$ 4,767
Contributions from noncontrolling interest	1,900
Changes in noncontrolling interest from acquisition		1,349
Distributions to noncontrolling interest	(7,554)	(7,879)
Redemptions	(255)	(1,368)
Essex Portfolio, L.P.
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	6,183,192	6,403,504
Net income	176,949	328,765
Change in fair value of derivatives and amortization of swap settlements	4,407	(8,782)
Change in fair value of marketable debt securities, net	85	(305)
Issuance of common stock under:
General partner's stock based compensation, net	(3,744)	8,665
Sale of common stock by general partner, net		(70)
Equity based compensation costs	5,082	1,698
Retirement of common units, net	(9,172)	$ (176,311)
Accounting standards update		us-gaap:AccountingStandardsUpdate201613Member
Cumulative effect upon adoption of ASU No. 2016-13	6,210,931	$ 6,417,949
Changes in the redemption value of redeemable noncontrolling interest	(4,083)	4,767
Contributions from noncontrolling interest	1,900
Changes in noncontrolling interest from acquisition		1,349
Distributions to noncontrolling interest	(2,760)	(3,107)
Redemptions	(255)	(1,368)
Partners' capital account, distributions declared	(140,670)	(140,666)
Balance at period end	$ 6,210,931	$ 6,417,949
Essex Portfolio, L.P. | Common Equity | General Partner
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning (in shares)	64,999	66,092
Balance at period beginning	$ 6,015,139	$ 6,234,315
Net income	$ 168,444	$ 315,006
Issuance of common stock under:
General partner's stock based compensation, net (in shares)	39	89
General partner's stock based compensation, net	$ (3,744)	$ 8,665
Sale of common stock by general partner, net		(70)
Equity based compensation costs	$ 5,028	$ 1,619
Retirement of common units, net (in shares)	(40)	(776)
Retirement of common units, net	$ (9,172)	$ (176,311)
Cumulative effect upon adoption of ASU No. 2016-13	6,035,566	6,250,833
Changes in the redemption value of redeemable noncontrolling interest	$ (4,178)	$ 4,741
Redemptions (in shares)	1	7
Redemptions	$ (75)	$ (1,048)
Partners' capital account, distributions declared	$ (135,876)	$ (135,894)
Balance at period end (in shares)	64,999	65,412
Balance at period end	$ 6,035,566	$ 6,250,833
Essex Portfolio, L.P. | Common Equity | Limited Partners
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning (in shares)	2,295	2,302
Balance at period beginning	$ 58,184	$ 57,359
Net income	5,947	$ 10,986
Issuance of common stock under:
Equity based compensation costs (in shares)		2
Equity based compensation costs	54	$ 79
Cumulative effect upon adoption of ASU No. 2016-13	59,328	63,550
Changes in the redemption value of redeemable noncontrolling interest	$ 73	$ (18)
Redemptions (in shares)	(1)	(8)
Redemptions	$ (136)	$ (84)
Partners' capital account, distributions declared	$ (4,794)	$ (4,772)
Balance at period end (in shares)	2,294	2,296
Balance at period end	$ 59,328	$ 63,550
Essex Portfolio, L.P. | Accumulated Other Comprehensive Loss
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	(11,303)	(10,432)
Change in fair value of derivatives and amortization of swap settlements	4,407	(8,782)
Change in fair value of marketable debt securities, net	85	(305)
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13	(6,811)	(19,519)
Balance at period end	(6,811)	(19,519)
Essex Portfolio, L.P. | Noncontrolling Interest
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning	121,172	122,262
Net income	2,558	2,773
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13	122,848	123,085
Changes in the redemption value of redeemable noncontrolling interest	22	44
Contributions from noncontrolling interest	1,900
Changes in noncontrolling interest from acquisition		1,349
Distributions to noncontrolling interest	(2,760)	(3,107)
Redemptions	(44)	(236)
Balance at period end	$ 122,848	123,085
Cumulative Effect, Period Of Adoption, Adjustment | Essex Portfolio, L.P.
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		(190)
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13		(190)
Cumulative Effect, Period Of Adoption, Adjustment | Essex Portfolio, L.P. | Common Equity | General Partner
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance at period beginning		(190)
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13		$ (190)