Equity, Capital and Other Interests EQR Common Shares (Details) - shares	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Common Shares of beneficial interest, shares outstanding	364,050,890	362,855,454
Common Shares Issued:
Conversion of OP Units	171,353
Exercise of share options	814,827
Employee Share Purchase Plan (ESPP)	40,873
Restricted Share Grants, net	169,667
Conversion of restricted shares to restricted units	(1,284)
Units
Common Shares And Units Outstanding	378,517,017
Units Ownership Interest in Operating Partnership	3.80%
Limited Partner [Member]
Limited Partners' Capital Account, Units Outstanding	14,466,127	14,298,691
Common Shares Issued:
Conversion of OP Units	(171,353)
Conversion of restricted shares to restricted units	1,284
Units
Restricted units, net	337,505