Reportable Segments - NOI from Our Rental Real Estate for Each Segment Specific to Continuing Operations (Parenthetical) (Details) - Property	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Units in same store properties	76,297	76,297	72,872

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