Equity and Redeemable Noncontrolling Interests of Equity Residential (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Common Shares of beneficial interest, shares outstanding	365,657,065	364,755,444
Common Shares Issued:
Conversion of OP Units	87,168
Exercise of share options	619,232
Employee Share Purchase Plan (ESPP)	46,399
Restricted share grants, net	148,822
Units
Common Shares And Units Outstanding	380,284,810
Units Ownership Interest in Operating Partnership	3.80%
Redeemable Noncontrolling Interests – Operating Partnership	$ 441,892	$ 566,783
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership	(113,308)
Change in carrying value of Redeemable Noncontrolling Interests – Operating Partnership	$ (11,583)
ERPOP [Member]
Common Shares Issued:
Conversion of OP Units	(87,168)
Exercise of share options	619,232
Employee Share Purchase Plan (ESPP)	46,399
Restricted share grants, net	148,822
Units
Total Units Outstanding	14,627,745	14,427,164
Restricted unit grants, net	287,749
Shares Issued During Period Shares Conversion Of Units To Common Shares	(87,168)
Common Shares And Units Outstanding	380,284,810	379,182,608
Units Ownership Interest in Operating Partnership	3.80%