Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net income	$ 187,551	$ 86,907
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	115,503	109,707
Amortization of discount on marketable securities and other investments	(3,573)	(3,756)
Amortization of (premium) discount and debt financing costs, net	(3,309)	(3,795)
Gain on sale of marketable securities and other investments	(1,605)	(740)
Company's share of gain on the sales of co-investments	0	(7,435)
Earnings from co-investments	(10,899)	(7,633)
Operating distributions from co-investments	12,358	9,753
Gain on the sale of real estate and land	(26,174)	(20,258)
Equity-based compensation	1,253	1,490
Gain on remeasurement of co-investment	(86,482)	0
Changes in operating assets and liabilities:
Prepaid expenses, receivables and other assets	(4,536)	846
Accounts payable and accrued liabilities	42,449	35,200
Other liabilities	737	324
Net cash provided by operating activities	223,273	200,610
Additions to real estate:
Acquisitions of real estate and acquisition related capital expenditures	(187,917)	(110,309)
Redevelopment	(12,240)	(24,151)
Development acquisitions of and additions to real estate under development	(30,457)	(22,656)
Capital expenditures on rental properties	(10,885)	(5,688)
Investments in notes receivable	(8,750)	0
Proceeds from insurance for property losses	435	435
Proceeds from dispositions of real estate	131,230	48,008
Contributions to co-investments	(120,816)	(50,591)
Changes in restricted cash and refundable deposits	89,985	59,346
Purchases of marketable securities	(20,939)	(1,344)
Sales and maturities of marketable securities and other investments	24,903	5,045
Non-operating distributions from co-investments	55,025	21,146
Net cash used in investing activities	(90,426)	(80,759)
Cash flows from financing activities:
Borrowings under debt agreements	654,562	305,895
Repayment of debt	(661,349)	(309,903)
Additions to deferred charges	(1,014)	(1,037)
Net proceeds from issuance of common stock	(65)	(134)
Net proceeds from stock options exercised	5,794	5,232
Distributions to noncontrolling interest	(5,425)	(4,858)
Redemption of noncontrolling interest	(1,070)	(1,089)
Common stock dividends paid	(104,857)	(95,476)
Net cash used in financing activities	(113,424)	(101,370)
Net increase in cash and cash equivalents	19,423	18,481
Cash and cash equivalents at beginning of period	64,921	29,683
Cash and cash equivalents at end of period	84,344	48,164
Supplemental disclosure of cash flow information:
Cash paid for interest, net of $3.3 million and $3.1 million capitalized in 2017 and 2016, respectively	48,397	48,109
Supplemental disclosure of noncash investing and financing activities:
Issuance of DownREIT units in connection with acquisition of real estate	22,506	0
Transfers between real estate under development to rental properties, net	747	107,643
Transfer from real estate under development to co-investments	2,080	2,338
Reclassifications to redeemable noncontrolling interest to or from additional paid in capital and noncontrolling interest	731	751
Debt assumed in connection with acquisition	51,882	48,832
Essex Portfolio, L.P. [Member]
Cash flows from operating activities:
Net income	187,551	86,907
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	115,503	109,707
Amortization of discount on marketable securities and other investments	(3,573)	(3,756)
Amortization of (premium) discount and debt financing costs, net	(3,309)	(3,795)
Gain on sale of marketable securities and other investments	(1,605)	(740)
Company's share of gain on the sales of co-investments	0	(7,435)
Earnings from co-investments	(10,899)	(7,633)
Operating distributions from co-investments	12,358	9,753
Gain on the sale of real estate and land	(26,174)	(20,258)
Equity-based compensation	1,253	1,490
Gain on remeasurement of co-investment	(86,482)	0
Changes in operating assets and liabilities:
Prepaid expenses, receivables and other assets	(4,536)	846
Accounts payable and accrued liabilities	42,449	35,200
Other liabilities	737	324
Net cash provided by operating activities	223,273	200,610
Additions to real estate:
Acquisitions of real estate and acquisition related capital expenditures	(187,917)	(110,309)
Redevelopment	(12,240)	(24,151)
Development acquisitions of and additions to real estate under development	(30,457)	(22,656)
Capital expenditures on rental properties	(10,885)	(5,688)
Investments in notes receivable	(8,750)	0
Proceeds from insurance for property losses	435	435
Proceeds from dispositions of real estate	131,230	48,008
Contributions to co-investments	(120,816)	(50,591)
Changes in restricted cash and refundable deposits	89,985	59,346
Purchases of marketable securities	(20,939)	(1,344)
Sales and maturities of marketable securities and other investments	24,903	5,045
Non-operating distributions from co-investments	55,025	21,146
Net cash used in investing activities	(90,426)	(80,759)
Cash flows from financing activities:
Borrowings under debt agreements	654,562	305,895
Repayment of debt	(661,349)	(309,903)
Additions to deferred charges	(1,014)	(1,037)
Net proceeds from issuance of common stock	(65)	(134)
Net proceeds from stock options exercised	5,794	5,232
Distributions to noncontrolling interest	(5,425)	(1,528)
Redemption of noncontrolling interest	(1,070)	(1,089)
Common stock dividends paid	(104,857)	(98,806)
Net cash used in financing activities	(113,424)	(101,370)
Cash acquired from consolidation of co-investment	0	0
Net increase in cash and cash equivalents	19,423	18,481
Cash and cash equivalents at beginning of period	64,921	29,683
Cash and cash equivalents at end of period	84,344	48,164
Supplemental disclosure of cash flow information:
Cash paid for interest, net of $3.3 million and $3.1 million capitalized in 2017 and 2016, respectively	48,397	48,109
Supplemental disclosure of noncash investing and financing activities:
Issuance of DownREIT units in connection with acquisition of real estate	22,506	0
Transfers between real estate under development to rental properties, net	747	107,643
Transfer from real estate under development to co-investments	2,080	2,338
Reclassifications to redeemable noncontrolling interest to or from additional paid in capital and noncontrolling interest	731	751
Debt assumed in connection with acquisition	$ 51,882	$ 48,832