Equity, Capital and Other Interests - Changes in Operating Partnership's Issued and Outstanding General Partner Units and Limited Partner Units (Details) - shares	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
General and Limited Partner Units
Exercise of share options	348,510	833,669
Employee Share Purchase Plan (ESPP)	35,669	47,761
Restricted share grants, net	175,970	87,377
Restricted unit grants, net	223,242	155,638
Common Shares And Units Outstanding	388,969,613	387,284,518
Limited Partner Units
Total Units Outstanding	12,659,027	13,858,073
Restricted unit grants, net	223,242	155,638
Conversion of Limited Partner OP Units to EQR Common Shares	(31,089)	(1,084,023)
Total Units Outstanding	12,851,180	12,929,688
Units Ownership Interest in Operating Partnership	3.30%	3.30%
ERPOP [Member]
General and Limited Partner Units
Common Shares And Units Outstanding	388,186,222	386,160,073
Exercise of share options	348,510	833,669
Employee Share Purchase Plan (ESPP)	35,669	47,761
Restricted share grants, net	175,970	87,377
Restricted unit grants, net	223,242	155,638
Common Shares And Units Outstanding	388,969,613	387,284,518
Limited Partner Units
Total Units Outstanding	12,659,027	13,858,073
Restricted unit grants, net	223,242	155,638
Conversion of Limited Partner OP Units to EQR Common Shares	(31,089)	(1,084,023)
Total Units Outstanding	12,851,180	12,929,688
Units Ownership Interest in Operating Partnership	3.30%	3.30%