Net Income Per Common Share and Net Income Per Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Basic:
Net income available to common stockholders/unitholders	$ 73,254	$ 168,444
Weighted average common shares/units (in shares)	65,275,775	64,989,620
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.12	$ 2.59
Effect of Dilutive Securities:
Stock options (in shares)	63,603	31,066
DownREIT units (in shares)	0	94,247
Diluted:
Net income available to common stockholders/unitholders	$ 73,254	$ 168,641
Weighted average common shares/units (in shares)	65,339,378	65,114,933
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.12	$ 2.59
Essex Portfolio, L.P.
Basic:
Net income available to common stockholders/unitholders	$ 75,817	$ 174,391
Weighted average common shares/units (in shares)	67,558,239	67,283,424
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.12	$ 2.59
Effect of Dilutive Securities:
Stock options (in shares)	63,603	31,066
DownREIT units (in shares)	0	94,247
Diluted:
Net income available to common stockholders/unitholders	$ 75,817	$ 174,588
Weighted average common shares/units (in shares)	67,621,842	67,408,737
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.12	$ 2.59
DownREIT Units
Effect of Dilutive Securities:
Income effect of Dilutive Securities	$ 0	$ 197
DownREIT Units | Essex Portfolio, L.P.
Effect of Dilutive Securities:
Income effect of Dilutive Securities	$ 0	$ 197
Convertible units
Diluted:
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	2,282,464	2,293,804
Income allocated to convertible OP Units	$ 2,600	$ 5,900
Stock options
Diluted:
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	79,687	349,252
Stock options | Essex Portfolio, L.P.
Diluted:
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	79,687	349,252