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v3.19.3.a.u2

Summary of Significant Accounting Policies Compensation (Parenthetical) (Details) | 12 Months Ended
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Dec. 31, 2019
Summary Of Significant Accounting Policies [Abstract] |
Historical period to estimate volatility | 5 years

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- Definition Historical volatility estimation period. + References No definition available. + Details
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Period Type: | duration

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- Definition Summary of significant accounting policies. + References No definition available. + Details
Name: | eqr_SummaryOfSignificantAccountingPoliciesAbstract
Namespace Prefix: | eqr_
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