The total number of rental properties that the Company disposed of to unaffiliated parties during the period.

No definition available.

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

- Definition

Total number of rental units associated with rental properties that the company disposed of to unaffiliated third parties during the period.

+ References

No definition available.

+ Details

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

- Definition

The cash inflow from the sale of real estate investment property.

+ References

No definition available.

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=eqr_ConsolidatedRentalPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events - Disposed Properties to Unaffiliated Parties (Details) $ in Thousands		9 Months Ended
	Oct. 01, 2025 USD ($) Property ApartmentUnit	Sep. 30, 2025 USD ($) ApartmentUnit	Sep. 30, 2024 Property
Subsequent Event [Line Items]
Properties disposed \| Property			5
Property Units disposed \| ApartmentUnit		1,330
Sales Price \| $		$ 598,750
Rental Properties - Consolidated [Member]
Subsequent Event [Line Items]
Properties disposed \| Property			5
Property Units disposed \| ApartmentUnit		1,330
Sales Price \| $		$ 594,450
Subsequent Events [Member] \| Rental Properties - Consolidated [Member]
Subsequent Event [Line Items]
Properties disposed \| Property	1
Property Units disposed \| ApartmentUnit	208
Sales Price \| $	$ 76,000