Reportable Segments - Schedule of Reconciliation of Total Assets and Capital Expenditures (Parenthetical) (Details) - Property	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Units in same store properties	75,362	75,362

Total number of units associated with properties acquired or completed and stabilized two or more fiscal years ago, less properties subsequently sold.

No definition available.

Name:	eqr_NumberOfUnitsInSameStoreProperties
Namespace Prefix:	eqr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration