Condensed Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Total revenues	$ 356,223	$ 347,255
Expenses:
Property operating, excluding real estate taxes	58,898	57,250
Real estate taxes	39,418	37,713
Corporate-level property management expenses	8,153	7,770
Depreciation and amortization	120,568	119,105
General and administrative	13,459	14,813
Expensed acquisition and investment related costs	32	57
Total expenses	240,528	236,708
Earnings from operations	115,695	110,547
Interest expense	(53,643)	(54,861)
Total return swap income	2,045	2,270
Interest and other income	12,261	5,909
Equity income from co-investments	16,276	32,774
Gain on early retirement of debt, net	1,336	0
Gain on remeasurement of co-investment	31,535	0
Net income	125,505	96,639
Net income attributable to noncontrolling interest	(6,647)	(5,721)
Net income available to common stockholders	118,858	90,918
Comprehensive income	123,668	102,815
Comprehensive income attributable to noncontrolling interest	(6,585)	(5,926)
Comprehensive income attributable to controlling interest	$ 117,083	$ 96,889
Basic:
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.81	$ 1.38
Weighted average number of shares/common units outstanding during the period (in shares)	65,702,788	66,044,022
Diluted:
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.81	$ 1.38
Weighted average number of shares/common units outstanding during the period (in shares)	65,783,869	66,082,517
Rental and Other Property Revenues [Member]
Revenues:
Total revenues	$ 353,888	$ 344,947
Management and Other Fees From Affiliates Income [Member]
Revenues:
Total revenues	2,335	2,308
Essex Portfolio, L.P. [Member]
Revenues:
Total revenues	356,223	347,255
Expenses:
Property operating, excluding real estate taxes	58,898	57,250
Real estate taxes	39,418	37,713
Corporate-level property management expenses	8,153	7,770
Depreciation and amortization	120,568	119,105
General and administrative	13,459	14,813
Expensed acquisition and investment related costs	32	57
Total expenses	240,528	236,708
Earnings from operations	115,695	110,547
Interest expense	(53,643)	(54,861)
Total return swap income	2,045	2,270
Interest and other income	12,261	5,909
Equity income from co-investments	16,276	32,774
Gain on early retirement of debt, net	1,336	0
Gain on remeasurement of co-investment	31,535	0
Net income	125,505	96,639
Net income attributable to noncontrolling interest	(2,476)	(2,589)
Net income available to common stockholders	123,029	94,050
Comprehensive income	123,668	102,815
Comprehensive income attributable to noncontrolling interest	(2,476)	(2,589)
Comprehensive income attributable to controlling interest	$ 121,192	$ 100,226
Basic:
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.81	$ 1.38
Weighted average number of shares/common units outstanding during the period (in shares)	68,007,852	68,317,435
Diluted:
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.81	$ 1.38
Weighted average number of shares/common units outstanding during the period (in shares)	68,088,933	68,355,930
Essex Portfolio, L.P. [Member] | Rental and Other Property Revenues [Member]
Revenues:
Total revenues	$ 353,888	$ 344,947
Essex Portfolio, L.P. [Member] | Management and Other Fees From Affiliates Income [Member]
Revenues:
Total revenues	$ 2,335	$ 2,308