Leases - Summary of Residential Bad Debt for Company's Properties (Parenthetical) (Details) $ in Millions	12 Months Ended
Dec. 31, 2021 USD ($)
Leases [Abstract]
Bad debt, net from resident payments	$ 34.8

Operating lease lease income bad debt net from resident payments.

No definition available.

Name:	eqr_OperatingLeaseLeaseIncomeBadDebtNetFromResidentPayments
Namespace Prefix:	eqr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration