Capital and Redeemable Limited Partners of ERP Operating Limited Partnership (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Common Shares And Units Outstanding	380,257,233
Exercise of EQR share options	599,634
EQR’s Employee Share Purchase Plan (ESPP)	33,065
Restricted share grants, net	152,653
Conversion of Limited Partner OP Units to EQR Common Shares	9,840
Units Ownership Interest in Operating Partnership	3.90%
ERPOP [Member]
Common Shares And Units Outstanding	380,257,233	379,182,608
Exercise of EQR share options	599,634
EQR’s Employee Share Purchase Plan (ESPP)	33,065
Restricted share grants, net	152,653
Restricted unit grants, net	289,273
Total Units Outstanding	14,706,597	14,427,164
Conversion of Limited Partner OP Units to EQR Common Shares	(9,840)
Units Ownership Interest in Operating Partnership	3.90%
Redeemable Limited Partners	$ 478,324	$ 566,783
Limited Partners Change In Redemption Value	(99,190)
Limited Partners Change In Carrying Value	$ 10,731