Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Cash flows from operating activities:
Net income	$ 134,438		$ 172,055		$ 139,590
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	360,592		193,518		170,686
Earnings from co-investments	(33,335)		(14,613)		(12,633)
Company's share of gain on the sales of co-investments	(6,558)		(41,252)		(29,112)
Operating distributions from co-investments	49,486		19,636		14,259
Gain on the sales of real estate and land	46,039		30,725		10,870
Loss on early retirement of debt, net	268		300		5,009
Gain on sale of marketable securities	(886)		(1,767)		(819)
Amortization of (premium) discount and financing costs, net	(14,672)		12,216		11,644
Amortization of discount on notes receivables	0		(844)		(1,832)
Amortization of discount on marketable securities	(9,325)		(6,556)		(5,127)
Non cash merger and integration expenses	9,025		0		0
Equity-based compensation	8,740		4,508		4,141
Gain on remeasurement of co-investment	0		0		(21,947)
Changes in operating assets and liabilities:
Prepaid expenses, in-place lease value, receivables and other assets	15,828		(1,588)		(9,488)
Accounts payable and accrued liabilities	24,233		72		12,360
Other liabilities	1,188		22		1,638
Net cash provided by operating activities	492,983		304,982		267,499
Additions to real estate:
Acquisitions of real estate	(387,547)		(348,774)		(393,771)
Redevelopment	(81,429)		(47,289)		(46,647)
Acquisition of and additions to real estate under development	(152,766)		(17,757)		(29,196)
Capital expenditures on rental properties	(78,864)		(56,919)		(45,368)
Proceeds from insurance for property losses	35,547		0		0
BRE merger consideration paid	(555,826)		0		0
Acquisition of membership interest in co-investment	0		0		(85,000)
Dispositions of real estate	141,189		65,496		27,800
Dispositions of co-investments	13,900		0		0
Changes in restricted cash and refundable deposits	(36,582)		(9,149)		(6,069)
Purchases of marketable securities	(20,516)		(16,442)		(73,735)
Sales and maturities of marketable securities	8,753		24,172		61,703
Purchases of and advances under notes and other receivables	0		(56,750)		(26,000)
Collections of notes and other receivables	76,585		53,438		14,525
Contributions to co-investments	(246,006)		(162,578)		(260,153)
Non-operating distributions from co-investments	136,406		118,856		49,773
Net cash used in investing activities	(1,147,156)		(453,696)		(812,138)
Cash flows from financing activities:
Borrowings under debt agreements	2,093,406		969,061		1,745,853
Repayment of debt	(1,814,020)		(750,900)		(1,371,317)
Additions to deferred charges	(17,402)		(7,402)		(6,707)
Equity related issuance cost	(1,391)		(617)		(309)
Net proceeds from stock options exercised	11,039		4,958		2,643
Net proceeds from issuance of common stock	532,770		138,366		357,720
Contributions from noncontrolling interest	0		0		2,400
Distributions to noncontrolling interest	(17,465)		(18,488)		(16,691)
Redemption of noncontrolling interest	(5,753)		(5,711)		(6,986)
Common and preferred stock dividends paid	(260,574)		(180,668)		(156,250)
Net cash provided by financing activities	520,610		148,599		550,356
Cash acquired from the BRE merger	140,353		0		0
Net increase (decrease) in cash and cash equivalents	6,790		(115)		5,717
Cash and cash equivalents at beginning of year	18,491		18,606		12,889
Cash and cash equivalents at end of year	25,281		18,491		18,606
Supplemental disclosure of cash flow information:
Cash paid for interest, net of capitalized interest	130,691		103,516		95,597
Interest capitalized	22,510		16,486		10,346
Supplemental disclosure of noncash investing and financing activities:
Contributions from noncontrolling interest	1,419,816	[1]	0	[1]	0	[1]
Retirement of noncontrolling interest	(1,419,816)	[1]	0	[1]	0	[1]
Transfer from real estate under development to rental properties	10,203	[1]	68	[1]	6,632	[1]
Transfer from real estate under development to co-investments	83,574	[1]	27,906	[1]	0	[1]
Transfer from co-investments to rental properties	0	[1]	0	[1]	148,053	[1]
Reclassification to redeemable noncontrolling interest from additional paid in capital and noncontrolling interest	18,766	[1]	0	[1]	0	[1]
Mortgage notes (excluding BRE merger) assumed in connection with purchases of real estate including the loan premiums recorded	72,568	[1]	0	[1]	82,133	[1]
Contribution of note receivable to co-investment	0	[1]	0	[1]	12,325	[1]
Change in accrual of dividends	37,594	[1]	5,575	[1]	5,441	[1]
Change in construction payable	22,845	[1]	2,655	[1]	1,113	[1]
Common stock proceeds receivables	1,258	[1]	0	[1]	0	[1]
Essex Portfolio, L.P. [Member]
Cash flows from operating activities:
Net income	134,438		172,055		139,590
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	360,592		193,518		170,686
Earnings from co-investments	(33,335)		(14,613)		(12,633)
Company's share of gain on the sales of co-investments	(6,558)		(41,252)		(29,112)
Operating distributions from co-investments	49,486		19,636		14,259
Gain on the sales of real estate and land	46,039		30,725		10,870
Loss on early retirement of debt, net	268		300		5,009
Gain on sale of marketable securities	(886)		(1,767)		(819)
Amortization of (premium) discount and financing costs, net	(14,672)		12,216		11,644
Amortization of discount on notes receivables	0		(844)		(1,832)
Amortization of discount on marketable securities	(9,325)		(6,556)		(5,127)
Non cash merger and integration expenses	9,025		0		0
Equity-based compensation	8,740		4,508		4,141
Gain on remeasurement of co-investment	0		0		(21,947)
Changes in operating assets and liabilities:
Prepaid expenses, in-place lease value, receivables and other assets	15,828		(1,588)		(9,488)
Accounts payable and accrued liabilities	24,233		72		12,360
Other liabilities	1,188		22		1,638
Net cash provided by operating activities	492,983		304,982		267,499
Additions to real estate:
Acquisitions of real estate	(387,547)		(348,774)		(393,771)
Redevelopment	(81,429)		(47,289)		(46,647)
Acquisition of and additions to real estate under development	(152,766)		(17,757)		(29,196)
Capital expenditures on rental properties	(78,864)		(56,919)		(45,368)
Proceeds from insurance for property losses	35,547		0		0
BRE merger consideration paid	(555,826)		0		0
Acquisition of membership interest in co-investment	0		0		(85,000)
Dispositions of real estate	141,189		65,496		27,800
Dispositions of co-investments	13,900		0		0
Changes in restricted cash and refundable deposits	(36,582)		(9,149)		(6,069)
Purchases of marketable securities	(20,516)		(16,442)		(73,735)
Sales and maturities of marketable securities	8,753		24,172		61,703
Purchases of and advances under notes and other receivables	0		(56,750)		(26,000)
Collections of notes and other receivables	76,585		53,438		14,525
Contributions to co-investments	(246,006)		(162,578)		(260,153)
Non-operating distributions from co-investments	136,406		118,856		49,773
Net cash used in investing activities	(1,147,156)		(453,696)		(812,138)
Cash flows from financing activities:
Borrowings under debt agreements	2,093,406		969,061		1,745,853
Repayment of debt	(1,814,020)		(750,900)		(1,371,317)
Additions to deferred charges	(17,402)		(7,402)		(6,707)
Equity related issuance cost	(1,391)		(617)		(309)
Net proceeds from stock options exercised	11,039		4,958		2,643
Net proceeds from issuance of common stock	532,770		138,366		357,720
Contributions from noncontrolling interest	0		0		2,400
Distributions to noncontrolling interest	(4,841)		(8,016)		(6,957)
Redemption of noncontrolling interest	(802)		(5,711)		(6,986)
Common and preferred stock dividends paid	(278,149)		(191,140)		(165,984)
Net cash provided by financing activities	520,610		148,599		550,356
Cash acquired from the BRE merger	140,353		0		0
Net increase (decrease) in cash and cash equivalents	6,790		(115)		5,717
Cash and cash equivalents at beginning of year	18,491		18,606		12,889
Cash and cash equivalents at end of year	25,281		18,491		18,606
Supplemental disclosure of cash flow information:
Cash paid for interest, net of capitalized interest	130,691		103,516		95,597
Interest capitalized	22,510		16,486		10,346
Supplemental disclosure of noncash investing and financing activities:
Contributions from noncontrolling interest	1,419,816	[1]	0	[1]	0	[1]
Retirement of noncontrolling interest	(1,419,816)	[1]	0	[1]	0	[1]
Transfer from real estate under development to rental properties	10,203	[1]	68	[1]	6,632	[1]
Transfer from real estate under development to co-investments	83,574	[1]	27,906	[1]	0	[1]
Transfer from co-investments to rental properties	0	[1]	0	[1]	148,053	[1]
Reclassification to redeemable noncontrolling interest from additional paid in capital and noncontrolling interest	18,766	[1]	0	[1]	0	[1]
Mortgage notes (excluding BRE merger) assumed in connection with purchases of real estate including the loan premiums recorded	72,568		0		82,133
Contribution of note receivable to co-investment	0		0		12,325
Change in accrual of dividends	37,594		5,575		5,441
Change in construction payable	22,845		2,655		1,113
Common stock proceeds receivables	$ 1,258		$ 0		$ 0

[1] See note 2(r) for details of noncash investing and financing activities related to the BRE merger.