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, 2025	Jun. 30, 2024
General and Limited Partner Units
Exercise of share options	83,754	119,516
Employee Share Purchase Plan (ESPP)	23,090	47,466
Restricted share grants, net	173,814	190,804
Restricted unit grants, net	286,898	172,667
Common Shares And Units Outstanding	391,586,712	390,750,724
Limited Partner Units
Total Units Outstanding	11,543,773	11,581,306
Restricted unit grants, net	286,898	172,667
Conversion of Limited Partner OP Units to EQR Common Shares	(224,399)	(90,131)
Total Units Outstanding	11,606,272	11,663,842
Units Ownership Interest in Operating Partnership	3.00%	3.00%
ERPOP [Member]
General and Limited Partner Units
Common Shares And Units Outstanding	391,019,156	390,872,723
Exercise of share options	83,754	119,516
Employee Share Purchase Plan (ESPP)	23,090	47,466
Restricted share grants, net	173,814	190,804
Restricted unit grants, net	286,898	172,667
OP Units repurchased and retired		(652,452)
Common Shares And Units Outstanding	391,586,712	390,750,724
Limited Partner Units
Total Units Outstanding	11,543,773	11,581,306
Restricted unit grants, net	286,898	172,667
Conversion of Limited Partner OP Units to EQR Common Shares	(224,399)	(90,131)
Total Units Outstanding	11,606,272	11,663,842
Units Ownership Interest in Operating Partnership	3.00%	3.00%