Organization and Basis of Presentation - Accumulated Other Comprehensive Loss (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	$ 6,183,192
Balance at period end	6,136,703
Accumulated Other Comprehensive Loss, Net
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	(14,729)
Other comprehensive income before reclassification	4,954
Amounts reclassified from accumulated other comprehensive loss	7
Other comprehensive income	4,961
Balance at period end	(9,768)
Change in fair value and amortization of swap settlements
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	(14,771)
Other comprehensive income before reclassification	4,706
Amounts reclassified from accumulated other comprehensive loss	7
Other comprehensive income	4,713
Balance at period end	(10,058)
Unrealized gain on available for sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	42
Other comprehensive income before reclassification	248
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	248
Balance at period end	290
Essex Portfolio, L.P. | Accumulated Other Comprehensive Loss, Net
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	(11,303)
Other comprehensive income before reclassification	5,129
Amounts reclassified from accumulated other comprehensive loss	7
Other comprehensive income	5,136
Balance at period end	(6,167)
Essex Portfolio, L.P. | Change in fair value and amortization of swap settlements
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	(11,346)
Other comprehensive income before reclassification	4,872
Amounts reclassified from accumulated other comprehensive loss	7
Other comprehensive income	4,879
Balance at period end	(6,467)
Essex Portfolio, L.P. | Unrealized gain on available for sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	43
Other comprehensive income before reclassification	257
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	257
Balance at period end	$ 300