Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 263,346	$ 163,731
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	233,442	219,380
Amortization of discount on marketable securities and other investments	(7,270)	(7,457)
Amortization of (premium) discount and debt financing costs, net	(4,317)	(7,598)
Gain on sale of marketable securities and other investments	(1,618)	(1,843)
Company's share of gain on the sales of co-investment	0	(13,046)
Earnings from co-investments	(21,207)	(16,318)
Operating distributions from co-investments	27,451	23,985
Gain on the sale of real estate and land	(26,174)	(20,258)
Equity-based compensation	3,361	3,198
Gain on remeasurement of co-investment	(88,641)	0
Changes in operating assets and liabilities:
Prepaid expenses, receivables and other assets	(3,326)	(3,942)
Accounts payable and accrued liabilities	(3,287)	9,772
Other liabilities	646	749
Net cash provided by operating activities	372,406	350,353
Additions to real estate:
Acquisitions of real estate and acquisition related capital expenditures	(193,527)	(117,349)
Redevelopment	(30,509)	(43,200)
Development acquisitions of and additions to real estate under development	(51,563)	(37,150)
Capital expenditures on rental properties	(25,648)	(22,277)
Investments in notes receivable	(12,750)	0
Proceeds from insurance for property losses	435	1,211
Proceeds from dispositions of real estate	131,230	48,008
Contributions to co-investments	(144,599)	(96,698)
Changes in restricted cash and refundable deposits	89,857	56,932
Purchases of marketable securities	(33,615)	(16,352)
Sales and maturities of marketable securities and other investments	28,766	11,179
Non-operating distributions from co-investments	67,674	34,564
Net cash used in investing activities	(174,249)	(181,132)
Cash flows from financing activities:
Borrowings under debt agreements	1,065,294	768,610
Repayment of debt	(1,004,966)	(501,167)
Repayment of cumulative redeemable preferred stock	0	(73,750)
Additions to deferred charges	(3,890)	(4,962)
Net proceeds from issuance of common stock	80,565	(279)
Net proceeds from stock options exercised	22,041	11,760
Distributions to noncontrolling interest	(14,371)	(12,880)
Redemption of noncontrolling interest	(3,528)	(2,233)
Redemption of redeemable noncontrolling interest	(720)	0
Common and preferred stock dividends paid	(219,618)	(201,488)
Net cash used in financing activities	(79,193)	(16,389)
Net increase in cash and cash equivalents	118,964	152,832
Cash and cash equivalents at beginning of period	64,921	29,683
Cash and cash equivalents at end of period	183,885	182,515
Supplemental disclosure of cash flow information:
Cash paid for interest, net of $6.6 million and $6.2 million capitalized in 2017 and 2016, respectively	106,448	93,031
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	1,540	108,402
Transfer from real estate under development to co-investments	3,340	4,485
Reclassifications to (from) redeemable noncontrolling interest to or from additional paid in capital and noncontrolling interest	1,117	(921)
Debt assumed in connection with acquisition	51,882	48,832
Essex Portfolio, L.P. [Member]
Cash flows from operating activities:
Net income	263,346	163,731
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	233,442	219,380
Amortization of discount on marketable securities and other investments	(7,270)	(7,457)
Amortization of (premium) discount and debt financing costs, net	(4,317)	(7,598)
Gain on sale of marketable securities and other investments	(1,618)	(1,843)
Company's share of gain on the sales of co-investment	0	(13,046)
Earnings from co-investments	(21,207)	(16,318)
Operating distributions from co-investments	27,451	23,985
Gain on the sale of real estate and land	(26,174)	(20,258)
Equity-based compensation	3,361	3,198
Gain on remeasurement of co-investment	(88,641)	0
Changes in operating assets and liabilities:
Prepaid expenses, receivables and other assets	(3,326)	(3,942)
Accounts payable and accrued liabilities	(3,287)	9,772
Other liabilities	646	749
Net cash provided by operating activities	372,406	350,353
Additions to real estate:
Acquisitions of real estate and acquisition related capital expenditures	(193,527)	(117,349)
Redevelopment	(30,509)	(43,200)
Development acquisitions of and additions to real estate under development	(51,563)	(37,150)
Capital expenditures on rental properties	(25,648)	(22,277)
Investments in notes receivable	(12,750)	0
Proceeds from insurance for property losses	435	1,211
Proceeds from dispositions of real estate	131,230	48,008
Contributions to co-investments	(144,599)	(96,698)
Changes in restricted cash and refundable deposits	89,857	56,932
Purchases of marketable securities	(33,615)	(16,352)
Sales and maturities of marketable securities and other investments	28,766	11,179
Non-operating distributions from co-investments	67,674	34,564
Net cash used in investing activities	(174,249)	(181,132)
Cash flows from financing activities:
Borrowings under debt agreements	1,065,294	768,610
Repayment of debt	(1,004,966)	(501,167)
Repayment of cumulative redeemable preferred stock	0	(73,750)
Additions to deferred charges	(3,890)	(4,962)
Net proceeds from issuance of common stock	80,565	(279)
Net proceeds from stock options exercised	22,041	11,760
Distributions to noncontrolling interest	(3,600)	(3,379)
Redemption of noncontrolling interest	(3,528)	(2,233)
Redemption of redeemable noncontrolling interest	(720)	0
Common and preferred stock dividends paid	(230,389)	(210,989)
Net cash used in financing activities	(79,193)	(16,389)
Net increase in cash and cash equivalents	118,964	152,832
Cash and cash equivalents at beginning of period	64,921	29,683
Cash and cash equivalents at end of period	183,885	182,515
Supplemental disclosure of cash flow information:
Cash paid for interest, net of $6.6 million and $6.2 million capitalized in 2017 and 2016, respectively	106,448	93,031
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	1,540	108,402
Transfer from real estate under development to co-investments	3,340	4,485
Reclassifications to (from) redeemable noncontrolling interest to or from additional paid in capital and noncontrolling interest	1,117	(921)
Debt assumed in connection with acquisition	$ 51,882	$ 48,832