Equity, Capital and Other Interests ERP Units (Details)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Capital Unit [Line Items]
Common Shares And Units Outstanding	375,523,508
Exercise of EQR share options	493,995
EQR's Employee Share Purchase Plan (ESPP)	37,928
Restricted Share Grants Net	162,349
OP Units repurchased and retired	(31,240)
Conversion Of Restricted Shares To Ltip Units Shares	(12,146)
Units Ownership Interest in Operating Partnership	3.80%
General And Limited Partner [Member]
Capital Unit [Line Items]
Common Shares And Units Outstanding	375,523,508	374,659,636
Exercise of EQR share options	493,995
EQR's Employee Share Purchase Plan (ESPP)	37,928
Restricted Share Grants Net	162,349
Issuance Of LTIPs	200,840
OP Units repurchased and retired	(31,240)
Limited Partner [Member]
Capital Unit [Line Items]
Issuance Of LTIPs	200,840
Conversion Of Restricted Shares To Ltip Units Shares	12,146
Shares Issued During Period Shares Conversion Of Units To Common Shares	(18,043)
Total Units Outstanding	14,375,319	14,180,376