Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Rental properties:
Land and land improvements	$ 1,354,748	$ 1,083,552
Buildings and improvements	5,286,033	4,360,205
Total rental properties	6,640,781	5,443,757
Less accumulated depreciation	(1,300,793)	(1,254,886)
Net real estate	5,339,988	4,188,871
Real estate under development	308,266	50,430
Co-investments	716,443	677,133
Total real estate	6,364,697	4,916,434
Cash and cash equivalents-unrestricted	19,918	18,491
Cash and cash equivalents-restricted	28,753	35,275
Marketable securities	100,348	90,084
Notes and other receivables	36,105	68,255
Prepaid expenses and other assets	54,024	33,781
Deferred charges, net	29,197	24,519
Total assets	6,633,042	5,186,839
Liabilities and Equity
Mortgage notes payable	1,408,232	1,404,080
Unsecured debt	1,410,162	1,410,023
Lines of credit	135,903	219,421
Accounts payable and accrued liabilities	83,470	67,183
Construction payable	7,671	8,047
Dividends payable	1,461	50,627
Derivative liabilities	2,109	2,682
Other liabilities	22,281	22,189
Total liabilities	3,071,289	3,184,252
Commitments and contingencies
Cumulative convertible Series G preferred stock	4,349	4,349
Equity:
Cumulative redeemable Series H preferred stock at liquidation value	73,750	73,750
Common stock, $.0001 par value, 656,020,000 shares authorized 38,392,134 and 37,421,219 shares issued and outstanding	4	4
Additional paid-in capital	2,505,003	2,345,763
Distributions in excess of accumulated earnings	(498,368)	(474,426)
Accumulated other comprehensive loss, net	(56,395)	(60,472)
Total stockholders' equity	2,023,994	1,884,619
Noncontrolling interest	1,533,410	113,619
Total equity	3,557,404	1,998,238
Total liabilities and equity	6,633,042	5,186,839
Essex Portfolio, L.P. [Member]
Rental properties:
Land and land improvements	1,354,748	1,083,552
Buildings and improvements	5,286,033	4,360,205
Total rental properties	6,640,781	5,443,757
Less accumulated depreciation	(1,300,793)	(1,254,886)
Net real estate	5,339,988	4,188,871
Real estate under development	308,266	50,430
Co-investments	716,443	677,133
Total real estate	6,364,697	4,916,434
Cash and cash equivalents-unrestricted	19,918	18,491
Cash and cash equivalents-restricted	28,753	35,275
Marketable securities	100,348	90,084
Notes and other receivables	36,105	68,255
Prepaid expenses and other assets	54,024	33,781
Deferred charges, net	29,197	24,519
Total assets	6,633,042	5,186,839
Liabilities and Equity
Mortgage notes payable	1,408,232	1,404,080
Unsecured debt	1,410,162	1,410,023
Lines of credit	135,903	219,421
Accounts payable and accrued liabilities	83,470	67,183
Construction payable	7,671	8,047
Distributions payable	1,461	50,627
Derivative liabilities	2,109	2,682
Other liabilities	22,281	22,189
Total liabilities	3,071,289	3,184,252
Commitments and contingencies
Cumulative convertible Series G preferred stock	4,349	4,349
Equity:
Limited Partners, Common equity	1,465,127	45,957
Accumulated other comprehensive loss, net	(54,617)	(58,940)
Total partners' capital	3,490,900	1,932,108
Noncontrolling interest	66,504	66,130
Total capital	3,557,404	1,998,238
Total liabilities and equity	6,633,042	5,186,839
Essex Portfolio, L.P. [Member] | General Partner [Member]
Equity:
General Partner	2,080,390	1,945,091
Essex Portfolio, L.P. [Member] | General Partner [Member] | Common Capital [Member]
Equity:
General Partner	2,009,181	1,873,882
Total capital	2,009,181	1,873,882
Essex Portfolio, L.P. [Member] | General Partner [Member] | Preferred Capital [Member]
Equity:
General Partner	71,209	71,209
Total capital	$ 71,209	$ 71,209