Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 248,239	$ 134,438	$ 172,055
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	453,423	360,592	193,518
Earnings from co-investments	(21,392)	(33,335)	(14,613)
Company's share of gain on the sales of co-investments	(469)	(6,558)	(41,252)
Operating distributions from co-investments	46,608	49,486	19,636
Gain on the sales of real estate and land	(47,333)	(46,039)	(30,725)
Loss on early retirement of debt, net	6,114	268	300
Gains on sale of marketable securities and other investments	(598)	(886)	(1,767)
Amortization of (premium) discount and financing costs, net	(19,361)	(14,672)	12,216
Amortization of discount on notes receivables	0	0	(844)
Amortization of discount on marketable securities and other investments	(12,389)	(9,325)	(6,556)
Non cash merger and integration expenses	0	9,025	0
Equity-based compensation	6,061	8,740	4,508
Gains on remeasurement of co-investment	(34,014)	0	0
Changes in operating assets and liabilities:
Prepaid expenses, in-place lease value, receivables and other assets	267	15,828	(1,588)
Accounts payable and accrued liabilities	(9,633)	24,233	72
Other liabilities	1,887	1,517	22
Net cash provided by operating activities	617,410	493,312	304,982
Additions to real estate:
Acquisitions of real estate and acquisition related capital expenditures	(515,726)	(387,547)	(348,774)
Redevelopment	(99,346)	(81,429)	(47,289)
Development acquisitions of and additions to real estate under development	(157,900)	(152,766)	(17,757)
Capital expenditures on rental properties	(57,277)	(78,864)	(56,919)
Proceeds from insurance for property losses	16,811	35,547	0
BRE merger consideration paid	0	(555,826)	0
Acquisition of membership interest in co-investment	(115,724)	0	0
Dispositions of real estate	319,008	141,189	65,496
Dispositions of co-investments	31,556	13,900	0
Changes in restricted cash and refundable deposits	(14,068)	(36,582)	(9,149)
Purchases of marketable securities	(14,300)	(20,516)	(16,442)
Sales and maturities of marketable securities and other investments	8,907	8,753	24,172
Purchases of and advances under notes and other receivables	0	0	(56,750)
Collections of notes and other receivables	0	76,585	53,438
Contributions to co-investments	(127,879)	(246,006)	(162,578)
Non-operating distributions from co-investments	382	136,406	118,856
Net cash used in investing activities	(725,556)	(1,147,156)	(453,696)
Cash flows from financing activities:
Borrowings under debt agreements	1,345,855	2,093,406	969,061
Repayment of debt	(1,197,351)	(1,814,020)	(750,900)
Additions to deferred charges	(8,034)	(17,402)	(7,402)
Net proceeds from stock options exercised	26,540	11,039	4,958
Net proceeds from issuance of common stock	332,137	531,379	137,749
Distributions to noncontrolling interest	(21,055)	(17,465)	(18,488)
Redemption of noncontrolling interest	(2,621)	(5,753)	(5,711)
Common and preferred stock dividends paid	(367,257)	(260,574)	(180,668)
Net cash provided by financing activities	108,214	520,610	148,599
Cash acquired from the BRE merger	0	140,353	0
Cash acquired from consolidation of co-investment	4,005	0	0
Net increase (decrease) in cash and cash equivalents	4,073	7,119	(115)
Cash and cash equivalents at beginning of year	25,610	18,491	18,606
Cash and cash equivalents at end of year	29,683	25,610	18,491
Supplemental disclosure of cash flow information:
Cash paid for interest, net of capitalized interest	181,106	130,691	103,516
Interest capitalized	15,571	22,510	16,486
Supplemental disclosure of noncash investing and financing activities:
Issuance of Operating Partnership units for contributed properties	0	1,419,816	0
Retirement of Operating Partnership units	0	(1,419,816)	0
Transfer from real estate under development to rental properties	308,704	10,203	68
Transfer from real estate under development to co-investments	6,234	83,574	27,906
Reclassification to redeemable noncontrolling interest from additional paid in capital and noncontrolling interest	22,387	18,766	0
Debt assumed in connection with acquisition of co-investment	114,435	0	0
Mortgage notes (excluding BRE merger) assumed in connection with purchases of real estate including the loan premiums recorded	0	72,568	0
Essex Portfolio, L.P. [Member]
Cash flows from operating activities:
Net income	248,239	134,438	172,055
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	453,423	360,592	193,518
Earnings from co-investments	(21,392)	(33,335)	(14,613)
Company's share of gain on the sales of co-investments	(469)	(6,558)	(41,252)
Operating distributions from co-investments	46,608	49,486	19,636
Gain on the sales of real estate and land	(47,333)	(46,039)	(30,725)
Loss on early retirement of debt, net	6,114	268	300
Gains on sale of marketable securities and other investments	(598)	(886)	(1,767)
Amortization of (premium) discount and financing costs, net	(19,361)	(14,672)	12,216
Amortization of discount on notes receivables	0	0	(844)
Amortization of discount on marketable securities and other investments	(12,389)	(9,325)	(6,556)
Non cash merger and integration expenses	0	9,025	0
Equity-based compensation	6,061	8,740	4,508
Gains on remeasurement of co-investment	(34,014)	0	0
Changes in operating assets and liabilities:
Prepaid expenses, in-place lease value, receivables and other assets	267	15,828	(1,588)
Accounts payable and accrued liabilities	(9,633)	24,233	72
Other liabilities	1,887	1,517	22
Net cash provided by operating activities	617,410	493,312	304,982
Additions to real estate:
Acquisitions of real estate and acquisition related capital expenditures	(515,726)	(387,547)	(348,774)
Redevelopment	(99,346)	(81,429)	(47,289)
Development acquisitions of and additions to real estate under development	(157,900)	(152,766)	(17,757)
Capital expenditures on rental properties	(57,277)	(78,864)	(56,919)
Proceeds from insurance for property losses	16,811	35,547	0
BRE merger consideration paid	0	(555,826)	0
Acquisition of membership interest in co-investment	(115,724)	0	0
Dispositions of real estate	319,008	141,189	65,496
Dispositions of co-investments	31,556	13,900	0
Changes in restricted cash and refundable deposits	(14,068)	(36,582)	(9,149)
Purchases of marketable securities	(14,300)	(20,516)	(16,442)
Sales and maturities of marketable securities and other investments	8,907	8,753	24,172
Purchases of and advances under notes and other receivables	0	0	(56,750)
Collections of notes and other receivables	0	76,585	53,438
Contributions to co-investments	(127,879)	(246,006)	(162,578)
Non-operating distributions from co-investments	382	136,406	118,856
Net cash used in investing activities	(725,556)	(1,147,156)	(453,696)
Cash flows from financing activities:
Borrowings under debt agreements	1,345,855	2,093,406	969,061
Repayment of debt	(1,197,351)	(1,814,020)	(750,900)
Additions to deferred charges	(8,034)	(17,402)	(7,402)
Net proceeds from stock options exercised	26,540	11,039	4,958
Net proceeds from issuance of common stock	332,137	531,379	137,749
Distributions to noncontrolling interest	(7,615)	(4,841)	(8,016)
Redemption of noncontrolling interest	(2,621)	(802)	(5,711)
Common and preferred stock dividends paid	(380,697)	(278,149)	(191,140)
Net cash provided by financing activities	108,214	520,610	148,599
Cash acquired from the BRE merger	0	140,353	0
Cash acquired from consolidation of co-investment	4,005	0	0
Net increase (decrease) in cash and cash equivalents	4,073	7,119	(115)
Cash and cash equivalents at beginning of year	25,610	18,491	18,606
Cash and cash equivalents at end of year	29,683	25,610	18,491
Supplemental disclosure of cash flow information:
Cash paid for interest, net of capitalized interest	181,106	130,691	103,516
Interest capitalized	15,571	22,510	16,486
Supplemental disclosure of noncash investing and financing activities:
Issuance of Operating Partnership units for contributed properties	0	1,419,816	0
Retirement of Operating Partnership units	0	(1,419,816)	0
Transfer from real estate under development to rental properties	308,704	10,203	68
Transfer from real estate under development to co-investments	6,234	83,574	27,906
Reclassification to redeemable noncontrolling interest from additional paid in capital and noncontrolling interest	22,387	18,766	0
Debt assumed in connection with acquisition of co-investment	114,435	0	0
Mortgage notes (excluding BRE merger) assumed in connection with purchases of real estate including the loan premiums recorded	$ 0	$ 72,568	$ 0