XML 82 R66.htm IDEA: XBRL DOCUMENT v3.21.1

Debt - Mortgage Notes Payable - Summary of Certain Interest Rate and Maturity Date Information (Details) - Mortgages [Member]	3 Months Ended
	Mar. 31, 2021
Debt Instrument [Line Items]
Weighted Average Interest Rate	3.18%
Maturity Date Ranges, Start	2022
Maturity Date Ranges, End	2061
Minimum [Member]
Debt Instrument [Line Items]
Interest Rate Ranges	0.05%
Maximum [Member]
Debt Instrument [Line Items]
Interest Rate Ranges	4.21%

X

- Definition

Debt instrument maturity year, end.

+ References

No definition available.

+ Details

Name:	eqr_DebtInstrumentMaturityYearEnd
Namespace Prefix:	eqr_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Debt instrument maturity year, start.

+ References

No definition available.

+ Details

Name:	eqr_DebtInstrumentMaturityYearStart
Namespace Prefix:	eqr_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- 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

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

X

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_MortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: