Condensed Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Total revenues	$ 361,635	$ 348,723	$ 717,858	$ 695,978
Expenses:
Property operating, excluding real estate taxes	59,162	58,111	118,060	115,361
Real estate taxes	36,285	36,035	75,703	73,748
Corporate-level property management expenses	8,212	7,782	16,365	15,552
Depreciation and amortization	119,465	119,330	240,033	238,435
General and administrative	13,927	11,125	27,386	25,938
Expensed acquisition and investment related costs	24	68	56	125
Total expenses	237,075	232,451	477,603	469,159
Gain on sale of real estate and land	0	22,244	0	22,244
Earnings from operations	124,560	138,516	240,255	249,063
Interest expense	(54,112)	(56,278)	(107,755)	(111,139)
Total return swap income	1,975	2,228	4,020	4,498
Interest and other income	8,347	6,895	20,608	12,804
Equity income from co-investments	16,959	15,049	33,235	47,823
Gain on early retirement of debt, net	332	0	1,668	0
Gain on remeasurement of co-investment	0	0	31,535	0
Net income	98,061	106,410	223,566	203,049
Net income attributable to noncontrolling interest	(5,786)	(5,970)	(12,433)	(11,691)
Net income available to common stockholders	92,275	100,440	211,133	191,358
Comprehensive income	93,740	109,793	217,408	212,608
Comprehensive income attributable to noncontrolling interest	(5,640)	(6,082)	(12,225)	(12,008)
Comprehensive income attributable to controlling interest	$ 88,100	$ 103,711	$ 205,183	$ 200,600
Basic:
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.40	$ 1.52	$ 3.21	$ 2.90
Weighted average number of shares/common units outstanding during the period (in shares)	65,718,806	66,047,751	65,710,842	66,045,897
Diluted:
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.40	$ 1.52	$ 3.21	$ 2.90
Weighted average number of shares/common units outstanding during the period (in shares)	65,821,815	66,096,349	65,802,417	66,088,803
Rental and Other Property Revenues [Member]
Revenues:
Total revenues	$ 359,375	$ 346,526	$ 713,263	$ 691,473
Management and Other Fees From Affiliates Income [Member]
Revenues:
Total revenues	2,260	2,197	4,595	4,505
Essex Portfolio, L.P. [Member]
Revenues:
Total revenues	361,635	348,723	717,858	695,978
Expenses:
Property operating, excluding real estate taxes	59,162	58,111	118,060	115,361
Real estate taxes	36,285	36,035	75,703	73,748
Corporate-level property management expenses	8,212	7,782	16,365	15,552
Depreciation and amortization	119,465	119,330	240,033	238,435
General and administrative	13,927	11,125	27,386	25,938
Expensed acquisition and investment related costs	24	68	56	125
Total expenses	237,075	232,451	477,603	469,159
Gain on sale of real estate and land	0	22,244	0	22,244
Earnings from operations	124,560	138,516	240,255	249,063
Interest expense	(54,112)	(56,278)	(107,755)	(111,139)
Total return swap income	1,975	2,228	4,020	4,498
Interest and other income	8,347	6,895	20,608	12,804
Equity income from co-investments	16,959	15,049	33,235	47,823
Gain on early retirement of debt, net	332	0	1,668	0
Gain on remeasurement of co-investment	0	0	31,535	0
Net income	98,061	106,410	223,566	203,049
Net income attributable to noncontrolling interest	(2,558)	(2,510)	(5,034)	(5,099)
Net income available to common stockholders	95,503	103,900	218,532	197,950
Comprehensive income	93,740	109,793	217,408	212,608
Comprehensive income attributable to noncontrolling interest	(2,558)	(2,510)	(5,034)	(5,099)
Comprehensive income attributable to controlling interest	$ 91,182	$ 107,283	$ 212,374	$ 207,509
Basic:
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.40	$ 1.52	$ 3.21	$ 2.90
Weighted average number of shares/common units outstanding during the period (in shares)	68,018,090	68,320,849	68,012,999	68,319,151
Diluted:
Net income available to common stockholders/unitholders (in dollars per share)	$ 1.40	$ 1.52	$ 3.21	$ 2.90
Weighted average number of shares/common units outstanding during the period (in shares)	68,121,099	68,369,447	68,104,574	68,362,057
Essex Portfolio, L.P. [Member] | Rental and Other Property Revenues [Member]
Revenues:
Total revenues	$ 359,375	$ 346,526	$ 713,263	$ 691,473
Essex Portfolio, L.P. [Member] | Management and Other Fees From Affiliates Income [Member]
Revenues:
Total revenues	$ 2,260	$ 2,197	$ 4,595	$ 4,505