Net Income Per Common Share and Net Income Per Common Unit - Schedule of Net Income Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Basic:
Net income available to common stockholders/unitholders	$ 164,621	$ 118,424	$ 589,093	$ 484,069
Weighted average common shares/units (in shares)	64,404,008	64,227,662	64,368,625	64,214,258
Per common share/unit amount (in dollars per share)	$ 2.56	$ 1.84	$ 9.15	$ 7.54
Diluted:
Net income available to common stockholders/unitholders	$ 164,621	$ 118,424	$ 589,093	$ 484,069
Weighted average common shares/units (in shares)	64,418,240	64,271,459	64,392,244	64,234,358
Per common share/unit amount (in dollars per share)	$ 2.56	$ 1.84	$ 9.15	$ 7.54
Essex Portfolio, L.P.
Basic:
Net income available to common stockholders/unitholders	$ 170,388	$ 122,630	$ 609,920	$ 501,144
Weighted average common shares/units (in shares)	66,660,423	66,508,041	66,643,952	66,480,312
Per common share/unit amount (in dollars per share)	$ 2.56	$ 1.84	$ 9.15	$ 7.54
Diluted:
Net income available to common stockholders/unitholders	$ 170,388	$ 122,630	$ 609,920	$ 501,144
Weighted average common shares/units (in shares)	66,674,655	66,551,838	66,667,571	66,500,412
Per common share/unit amount (in dollars per share)	$ 2.56	$ 1.84	$ 9.15	$ 7.54
Stock options
Basic:
Effect of dilutive securities	$ 0	$ 0	$ 0	$ 0
Effect of dilutive securities (in shares)	14,232	43,797	23,619	20,100
Stock options | Essex Portfolio, L.P.
Basic:
Effect of dilutive securities	$ 0	$ 0	$ 0	$ 0
Effect of dilutive securities (in shares)	14,232	43,797	23,619	20,100