Equity, Capital and Other Interests - Changes in Operating Partnership's Issued and Outstanding General Partner Units and Limited Partner Units (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
General and Limited Partner Units
Exercise of share options	234,395	381,384
Employee Share Purchase Plan (ESPP)	48,835	49,662
Restricted share grants, net	148,304	173,351
Restricted unit grants, net	166,344	223,242
Common Shares And Units Outstanding	391,457,323	389,013,861
Limited Partner Units
Total Units Outstanding	12,429,737	12,659,027
Restricted unit grants, net	166,344	223,242
Conversion of Limited Partner OP Units to EQR Common Shares	(862,596)	(37,661)
Total Units Outstanding	11,733,485	12,844,608
Units Ownership Interest in Operating Partnership	3.00%	3.30%
ERPOP [Member]
General and Limited Partner Units
Common Shares And Units Outstanding	390,859,445	388,186,222
Exercise of share options	234,395	381,384
Employee Share Purchase Plan (ESPP)	48,835	49,662
Restricted share grants, net	148,304	173,351
Restricted unit grants, net	166,344	223,242
Common Shares And Units Outstanding	391,457,323	389,013,861
Limited Partner Units
Total Units Outstanding	12,429,737	12,659,027
Restricted unit grants, net	166,344	223,242
Conversion of Limited Partner OP Units to EQR Common Shares	(862,596)	(37,661)
Total Units Outstanding	11,733,485	12,844,608
Units Ownership Interest in Operating Partnership	3.00%	3.30%