Equity, Capital and Other Interests - Changes in Operating Partnership's Issued and Outstanding General Partner Units and Limited Partner Units (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
General and Limited Partner Units
Common Shares And Units Outstanding	390,859,445	388,186,222
Issuance of OP Units		1,740,550
Exercise of share options	495,690	468,021	1,710,692
Employee Share Purchase Plan (ESPP)	68,136	66,835	70,702
Restricted share grants, net	148,474	174,575	89,593
Restricted unit grants, net	165,364	223,242	155,162
Common Shares And Units Outstanding	390,872,723	390,859,445	388,186,222
Limited Partner Units
Total Units Outstanding	12,429,737	12,659,027	13,858,073
Restricted unit grants, net	165,364	223,242	155,162
Conversion of Limited Partner OP Units to EQR Common Shares	(1,013,795)	(452,532)	(1,354,208)
Total Units Outstanding	11,581,306	12,429,737	12,659,027
Units Ownership Interest in Operating Partnership	3.00%	3.20%	3.30%
ERPOP [Member]
General and Limited Partner Units
Common Shares And Units Outstanding	390,859,445	388,186,222	386,160,073
Issuance of OP Units		1,740,550
Exercise of share options	495,690	468,021	1,710,692
Employee Share Purchase Plan (ESPP)	68,136	66,835	70,702
Restricted share grants, net	148,474	174,575	89,593
Restricted unit grants, net	165,364	223,242	155,162
Common Shares And Units Outstanding	390,872,723	390,859,445	388,186,222
OP Units repurchased and retired	(864,386)
Limited Partner Units
Total Units Outstanding	12,429,737	12,659,027	13,858,073
Restricted unit grants, net	165,364	223,242	155,162
Conversion of Limited Partner OP Units to EQR Common Shares	(1,013,795)	(452,532)	(1,354,208)
Total Units Outstanding	11,581,306	12,429,737	12,659,027
Units Ownership Interest in Operating Partnership	3.00%	3.20%	3.30%