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Schedule III - Real Estate and Accumulated Depreciation-Encumbrances Reconciliation (Parenthetical) (Details) $ in Millions | 12 Months Ended
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Dec. 31, 2021 USD ($)
Archstone Master Property [Member] |
Real Estate And Accumulated Depreciation [Line Items] |
Temporary letter of credit | $ 60.0

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- Definition Temporary letter of credit. + References No definition available. + Details
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Namespace Prefix: | eqr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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Namespace Prefix: | srt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |