Equity and Redeemable Noncontrolling Interests of Equity Residential (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Common Shares of beneficial interest, shares outstanding	365,496,019	364,755,444
Common Shares Issued:
Conversion of OP Units	5,577
Exercise of share options	582,435
Employee Share Purchase Plan (ESPP)	15,506
Restricted share grants, net	137,057
Units
Common Shares And Units Outstanding	380,199,636
Units Ownership Interest in Operating Partnership	3.90%
Redeemable Noncontrolling Interests Operating Partnership	$ 521,080	$ 566,783
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership	(55,478)
Change in carrying value of Redeemable Noncontrolling Interests – Operating Partnership	$ 9,775
ERPOP [Member]
Common Shares Issued:
Conversion of OP Units	(5,577)
Exercise of share options	582,435
Employee Share Purchase Plan (ESPP)	15,506
Restricted share grants, net	137,057
Units
Total Units Outstanding	14,703,617	14,427,164
Restricted unit grants, net	282,030
Shares Issued During Period Shares Conversion Of Units To Common Shares	(5,577)
Common Shares And Units Outstanding	380,199,636	379,182,608
Units Ownership Interest in Operating Partnership	3.90%