Commitments to Acquire/Dispose of Real Estate - Separate Agreement to Dispose of (Details) - Subsequent Event [Member] $ in Thousands	Apr. 27, 2018 USD ($)
Property/Unit schedule
Sales Price	$ 2,700
Land [Member]
Property/Unit schedule
Sales Price	$ 2,700

The amount of the fixed and determinable portion of an unrecorded sales commitment for the disposition of a rental property, land parcel or other property subsequent to the balance sheet date.

No definition available.

Name:	eqr_SalesPriceForCommitmentsToDispose
Namespace Prefix:	eqr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant