XML 107 R88.htm IDEA: XBRL DOCUMENT v3.10.0.1

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)
Fair Value Hedges [Member]
Derivative [Line Items]
Current Notional Balance	$ 450,000,000
Maturity Date	2019
Fair Value Hedges [Member] | Minimum [Member]
Derivative [Line Items]
Interest Rate	2.375%
Fair Value Hedges [Member] | Maximum [Member]
Derivative [Line Items]
Interest Rate	2.375%
Forward Starting Swaps [Member]
Derivative [Line Items]
Current Notional Balance	$ 500,000,000
Maturity Date	2029
Forward Starting Swaps [Member] | Minimum [Member]
Derivative [Line Items]
Interest Rate	2.2665%
Forward Starting Swaps [Member] | Maximum [Member]
Derivative [Line Items]
Interest Rate	3.1163%

X

- Definition

Maturity date, derivative.

+ References

No definition available.

+ Details

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

X

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_FairValueHedgingMember
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:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=eqr_ForwardStartingSwapsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: