XML 48 R53.htm IDEA: XBRL DOCUMENT v2.4.1.9

Derivative and Other Fair Value Instruments (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Derivative [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.584%us-gaap_DebtInstrumentInterestRateStatedPercentage
Debt Instrument, Maturity Date	May 01, 2061
2.375% Notes [Member]
Derivative [Line Items]
Proceeds from Issuance of Unsecured Debt	450,000,000us-gaap_ProceedsFromIssuanceOfUnsecuredDebt / us-gaap_LongtermDebtTypeAxis = eqr_A2.375NotesMember
Debt Instrument, Interest Rate, Stated Percentage	2.375%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = eqr_A2.375NotesMember
Derivative, Variable Interest Rate	0.61%us-gaap_DerivativeVariableInterestRate / us-gaap_LongtermDebtTypeAxis = eqr_A2.375NotesMember
Debt Instrument, Maturity Date	Jul. 01, 2019
Fair Value Hedging [Member]
Derivative [Line Items]
Current Notional Balance	450,000,000invest_DerivativeNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_FairValueHedgingMember
Lowest Possible Notional	450,000,000eqr_LowestPossibleNotional / us-gaap_DerivativeByNatureAxis = us-gaap_FairValueHedgingMember
Highest Possible Notional	450,000,000eqr_HighestPossibleNotional / us-gaap_DerivativeByNatureAxis = us-gaap_FairValueHedgingMember
Lowest Interest Rate	2.375%us-gaap_DerivativeLowerFixedInterestRateRange / us-gaap_DerivativeByNatureAxis = us-gaap_FairValueHedgingMember
Highest Interest Rate	2.375%us-gaap_DerivativeHigherFixedInterestRateRange / us-gaap_DerivativeByNatureAxis = us-gaap_FairValueHedgingMember
Earliest Maturity Date	P2019Y0M0D
Latest Maturity Date	P2019Y0M0D
Forward Starting Swaps [Member]
Derivative [Line Items]
Current Notional Balance	450,000,000invest_DerivativeNotionalAmount / us-gaap_DerivativeByNatureAxis = eqr_ForwardStartingSwapsMember
Lowest Possible Notional	450,000,000eqr_LowestPossibleNotional / us-gaap_DerivativeByNatureAxis = eqr_ForwardStartingSwapsMember
Highest Possible Notional	450,000,000eqr_HighestPossibleNotional / us-gaap_DerivativeByNatureAxis = eqr_ForwardStartingSwapsMember
Lowest Interest Rate	1.935%us-gaap_DerivativeLowerFixedInterestRateRange / us-gaap_DerivativeByNatureAxis = eqr_ForwardStartingSwapsMember
Highest Interest Rate	3.191%us-gaap_DerivativeHigherFixedInterestRateRange / us-gaap_DerivativeByNatureAxis = eqr_ForwardStartingSwapsMember
Earliest Maturity Date	P2025Y0M0D
Latest Maturity Date	P2025Y0M0D

X

- Definition

The earliest maturity date on derivatives designated as fair value or cash flow hedging instruments.

+ References

No definition available.

+ Details

Name:	eqr_EarliestMaturityDate
Namespace Prefix:	eqr_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Highest possible notional amount of all derivatives designated as fair value or cash flow hedging instruments. The notional amount relates to a number of currency units, shares, bushels, pounds or other units specified in a derivative instrument.

+ References

No definition available.

+ Details

Name:	eqr_HighestPossibleNotional
Namespace Prefix:	eqr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The latest maturity date on derivatives designated as fair value or cash flow hedging instruments.

+ References

No definition available.

+ Details

Name:	eqr_LatestMaturityDate
Namespace Prefix:	eqr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Lowest possible notional amount of all derivatives designated as fair value or cash flow hedging instruments. The notional amount relates to a number of currency units, shares, bushels, pounds or other units specified in a derivative instrument.

+ References

No definition available.

+ Details

Name:	eqr_LowestPossibleNotional
Namespace Prefix:	eqr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-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=6877327&loc=d3e13212-122682

+ Details

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

X

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

X

- Definition

High end of the range of fixed interest rates when a range is presented for a group of interest rate derivatives.

+ References

No definition available.

+ Details

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

X

- Details

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

X

- Definition

Low end of the range of fixed interest rates when a range is presented for a group of interest rate derivatives.

+ References

No definition available.

+ Details

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

X

- Definition

Variable interest rate in effect as of the balance sheet date related to the interest rate derivative.

+ References

No definition available.

+ Details

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

X

- Definition

The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfUnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

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

X

- Details

Name:	us-gaap_DerivativeByNatureAxis=us-gaap_FairValueHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=eqr_A2.375NotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: