Employee Plans - Summary of Information Regarding the Common Shares Issued Under the ESPP (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement, Additional Disclosure [Abstract]
Shares issued	68,136	66,835	70,702
Issuance price ranges, Minimum	$ 47.97	$ 52.33	$ 53.13
Issuance price ranges, Maximum	$ 55.11	$ 72.51	$ 71.04
Issuance proceeds	$ 3,517	$ 4,178	$ 4,265

Represents the maximum price that employees purchase common stock for under the employee purchase plan during the year.

No definition available.

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Namespace Prefix:	eqr_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the minimum price that employees purchase common stock for under the employee purchase plan during the year.

+ References

No definition available.

+ Details

Name:	eqr_EmployeeSharePurchasePlanIssuancePriceMinimum
Namespace Prefix:	eqr_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

Amount of cash inflow from issuance of shares under share-based payment arrangement. Excludes option exercised.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-14

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2A
-Subparagraph (a)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2A

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of shares issued under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration