Organization and Basis of Presentation - Accumulated Other Comprehensive Loss (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	$ 6,183,192
Balance at period end	6,210,931
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	4,337
Amounts reclassified from accumulated other comprehensive loss	2
Other comprehensive income	4,339
Balance at period end	(10,390)
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	4,255
Amounts reclassified from accumulated other comprehensive loss	2
Other comprehensive income	4,257
Balance at period end	(10,514)
Unrealized gain/(loss) 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	82
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	82
Balance at period end	124
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	4,490
Amounts reclassified from accumulated other comprehensive loss	2
Other comprehensive income	4,492
Balance at period end	(6,811)
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	4,405
Amounts reclassified from accumulated other comprehensive loss	2
Other comprehensive income	4,407
Balance at period end	(6,939)
Essex Portfolio, L.P. | Unrealized gain/(loss) 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	85
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	85
Balance at period end	$ 128