CONSOLIDATED STATEMENT OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - 6 months ended Jun. 30, 2017 - USD ($) $ in Thousands	Total	ERPOP [Member]	PREFERRED SHARES ERPOP [Member]	General Partner [Member] ERPOP [Member]	Limited Partner [Member] ERPOP [Member]	ACCUMULATED OTHER COMPREHENSIVE (LOSS) [Member] ERPOP [Member]	PARTIALLY OWNED PROPERTIES [Member] ERPOP [Member]
Balance, beginning of year at Dec. 31, 2016			$ 37,280	$ 10,305,707	$ 221,297	$ (113,909)
Balance, beginning of year at Dec. 31, 2016							$ 10,609
OP Unit Issuance:
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				14,622	(14,622)
Exercise of EQR share options				8,143
EQR's Employee Share Purchase Plan (ESPP)				2,111
Share-based employee compensation expense:
EQR restricted shares				5,382
EQR share options				5,979
EQR ESPP discount				414
Net income available to Units – General Partner		$ 338,237		338,237
OP Units – General Partner distributions				(369,964)
Offering costs				(36)
Supplemental Executive Retirement Plan (SERP)				(666)
Change in market value of Redeemable Limited Partners				30,351
Adjustment for Limited Partners ownership in Operating Partnership				14,096	(14,096)
LIMITED PARTNERS
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				14,622	(14,622)
Equity compensation associated with Units – Limited Partners					5,869
Net income available to Units – Limited Partners		12,765			12,765
Units – Limited Partners distributions					(13,386)
Change in carrying value of Redeemable Limited Partners					31,222
Adjustment for Limited Partners ownership in Operating Partnership				14,096	(14,096)
Accumulated other comprehensive income – derivative instruments:
Unrealized holding gains (losses) arising during the period	$ 3,507	3,507				3,507
Losses reclassified into earnings from other comprehensive income	(9,251)	(9,251)				9,251
NONCONTROLLING INTERESTS – PARTIALLY OWNED PROPERTIES
Net income attributable to Noncontrolling Interests	354,101	354,101					1,553
Contributions – Noncontrolling Interests – Partially Owned Properties	$ 125	$ 125					125
Distributions to Noncontrolling Interests							(5,984)
Balance, end of period at Jun. 30, 2017			$ 37,280	$ 10,354,376	$ 229,049	$ (101,151)
Balance, end of period at Jun. 30, 2017							$ 6,303