Reportable Segments - NOI from Our Rental Real Estate for Each Segment Specific to Continuing Operations (Parenthetical) (Details) - Property	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Units in same store properties	72,872	72,872	74,077

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