Equity, Capital and Other Interests ERP Units (Details)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Capital Unit [Line Items]
Common Shares And Units Outstanding	376,533,153
Exercise of EQR share options	1,476,512
EQR's Employee Share Purchase Plan (ESPP)	56,945
Restricted Share Grants Net	170,460
OP Units repurchased and retired	(31,240)
Conversion Of Restricted Shares To Ltip Units Shares	(12,146)
Shares Issued During Period Shares Conversion Of Units To Common Shares	68,296
Units Ownership Interest in Operating Partnership	3.80%
Limited Partner [Member]
Capital Unit [Line Items]
Limited Partners' Capital Account, Units Outstanding	14,325,066	14,180,376
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	(68,296)
General And Limited Partner [Member]
Capital Unit [Line Items]
Common Shares And Units Outstanding	376,533,153	374,659,636
Exercise of EQR share options	1,476,512
EQR's Employee Share Purchase Plan (ESPP)	56,945
Restricted Share Grants Net	170,460
Issuance Of LTIPs	200,840
OP Units repurchased and retired	(31,240)