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Percentage points of line of credit facility commitment fee.

No definition available.

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Short-Term financing which is expected to be paid back relatively quickly, such as by a subsequent longer-term loan. Also called swing loan or bridge financing.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
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Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
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Weighted average interest rate of debt outstanding.

No definition available.

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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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 8
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-URI https://asc.fasb.org/1943274/2147480657/210-10-S50-8

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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Name:	dei_LegalEntityAxis=eqr_ERPOPMember
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Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_BusinessAcquisitionAxis=eqr_MergerAgreementMember
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Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DebtInstrumentAxis=eqr_SeniorUnsecuredBridgeLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
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