XML 113 R93.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Details) | 12 Months Ended
--- | ---
Dec. 31, 2017 USD ($)
Fair Value Hedges [Member] |
Derivative [Line Items] |
Current Notional Balance | $ 450,000,000
Earliest Maturity Date | 2019
Latest 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 | $ 250,000,000
Earliest Maturity Date | 2028
Latest Maturity Date | 2029
Forward Starting Swaps [Member] | Minimum [Member] |
Derivative [Line Items] |
Interest Rate | 2.1478%
Forward Starting Swaps [Member] | Maximum [Member] |
Derivative [Line Items] |
Interest Rate | 2.2895%

X
- Definition Maturity date derivative earliest. + References No definition available. + Details
Name: | eqr_MaturityDateDerivativeEarliest
Namespace Prefix: | eqr_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maturity date derivative latest. + References No definition available. + Details
Name: | eqr_MaturityDateDerivativeLatest
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: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_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: |