Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Rental properties:
Land and land improvements	$ 2,573,923	$ 2,522,842
Buildings and improvements	10,052,754	9,808,627
Total rental properties	12,626,677	12,331,469
Less accumulated depreciation	(2,051,802)	(1,949,892)
Net real estate	10,574,875	10,381,577
Real estate under development	145,711	242,326
Co-investments	1,069,684	1,036,047
Real estate held for sale, net	0	26,879
Total real estate	11,790,270	11,686,829
Cash and cash equivalents-unrestricted	48,164	29,683
Cash and cash equivalents-restricted	32,319	93,372
Marketable securities	138,597	137,485
Notes and other receivables	18,198	19,285
Prepaid expenses and other assets	39,936	38,437
Total assets	12,067,484	12,005,091
Liabilities
Unsecured debt, net	2,936,463	3,088,680
Mortgage notes payable, net	2,252,057	2,215,077
Lines of credit, net	164,282	11,707
Accounts payable and accrued liabilities	170,444	131,415
Construction payable	36,822	40,953
Dividends payable	111,409	100,266
Other liabilities	34,814	34,518
Cumulative redeemable 7.125% Series H preferred stock at liquidation value	73,750	0
Total liabilities	$ 5,780,041	$ 5,622,616
Commitments and contingencies
Redeemable noncontrolling interest	$ 46,203	$ 45,452
Equity:
Common stock; $0.0001 par value, 656,020,000 shares authorized; 65,426,726 and 65,379,359 shares issued and outstanding, respectively	6	6
Cumulative redeemable 7.125% Series H preferred stock at liquidation value	0	73,750
Additional paid-in capital	7,010,181	7,003,317
Distributions in excess of accumulated earnings	(824,046)	(797,329)
Accumulated other comprehensive loss, net	(44,149)	(42,011)
Total stockholders' equity	6,141,992	6,237,733
Noncontrolling interest	99,248	99,290
Total equity	6,241,240	6,337,023
Total liabilities and equity	12,067,484	12,005,091
Essex Portfolio, L.P. [Member]
Rental properties:
Land and land improvements	2,573,923	2,522,842
Buildings and improvements	10,052,754	9,808,627
Total rental properties	12,626,677	12,331,469
Less accumulated depreciation	(2,051,802)	(1,949,892)
Net real estate	10,574,875	10,381,577
Real estate under development	145,711	242,326
Co-investments	1,069,684	1,036,047
Real estate held for sale, net	0	26,879
Total real estate	11,790,270	11,686,829
Cash and cash equivalents-unrestricted	48,164	29,683
Cash and cash equivalents-restricted	32,319	93,372
Marketable securities	138,597	137,485
Notes and other receivables	18,198	19,285
Prepaid expenses and other assets	39,936	38,437
Total assets	12,067,484	12,005,091
Liabilities
Unsecured debt, net	2,936,463	3,088,680
Mortgage notes payable, net	2,252,057	2,215,077
Lines of credit, net	164,282	11,707
Accounts payable and accrued liabilities	170,444	131,415
Construction payable	36,822	40,953
Dividends payable	111,409	100,266
Other liabilities	34,814	34,518
Cumulative redeemable 7.125% Series H preferred stock at liquidation value	73,750	0
Total liabilities	$ 5,780,041	$ 5,622,616
Commitments and contingencies
Redeemable noncontrolling interest	$ 46,203	$ 45,452
Equity:
General Partner	6,186,141	6,279,744
Common equity (2,224,968 and 2,214,545 units issued and outstanding, respectively)	46,889	47,235
Accumulated other comprehensive loss, net	(41,809)	(39,598)
Total partners' capital	6,191,221	6,287,381
Noncontrolling interest	50,019	49,642
Total capital	6,241,240	6,337,023
Total liabilities and equity	12,067,484	12,005,091
Essex Portfolio, L.P. [Member] | General Partner [Member] | Common Capital [Member]
Equity:
General Partner	6,186,141	6,208,535
Total capital	6,186,141	6,208,535
Essex Portfolio, L.P. [Member] | General Partner [Member] | Preferred Capital [Member]
Equity:
General Partner	0	71,209
Total capital	$ 0	$ 71,209