Investments in Partially Owned Entities - Summary of Information on Total Unconsolidated Development Joint Ventures Entered (Details) $ in Thousands	12 Months Ended
Dec. 31, 2021 USD ($) JointVenture
Variable Interest Entity [Line Items]
EQR's investments in unconsolidated entities – acquisitions	$ 48,534
Unconsolidated VIE [Member]
Variable Interest Entity [Line Items]
Number of unconsolidated joint ventures \| JointVenture	6
Unconsolidated VIE [Member] \| Equity Residential [Member]
Variable Interest Entity [Line Items]
EQR's investments in unconsolidated entities – acquisitions	$ 48,534

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585

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