v2.4.0.8

Variable Interest Entities (Narrative) (Details) (USD $) In Millions, unless otherwise specified | 9 Months Ended
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Sep. 30, 2014
Cinergy Receivables [Member] |
Variable Interest Entities [Line Items] |
Minimum equity balance required by Cinergy Receivables | $ 3
Line of Credit Facility, Expiration Date | Nov. 01, 2016
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member] |
Variable Interest Entities [Line Items] |
Percent of proceeds received as cash | 75.00%
Percent of proceeds received as subordinated note | 25.00%
Duke Energy Carolinas [Member] | DERF [Member] | Variable Interest Entity, Primary Beneficiary [Member] |
Variable Interest Entities [Line Items] |
Line of Credit Facility, Expiration Date | Oct. 01, 2016
Duke Energy Progress [Member] | DEPR [Member] | Variable Interest Entity, Primary Beneficiary [Member] |
Variable Interest Entities [Line Items] |
Line of Credit Facility, Expiration Date | Dec. 01, 2016
Duke Energy Florida [Member] | DEFR [Member] | Variable Interest Entity, Primary Beneficiary [Member] |
Variable Interest Entities [Line Items] |
Line of Credit Facility, Expiration Date | Mar. 01, 2017
Duke Energy Ohio [Member] | Cinergy Receivables [Member] |
Variable Interest Entities [Line Items] |
Fixed interest rate added to LIBOR to compute variable rate | 1.00%
Duke Energy Ohio [Member] | Other VIEs [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] |
Variable Interest Entities [Line Items] |
Ownership interest in OVEC | 9.00%
Duke Energy Indiana [Member] | Cinergy Receivables [Member] |
Variable Interest Entities [Line Items] |
Fixed interest rate added to LIBOR to compute variable rate | 1.00%

X
- Definition Percent of proceeds from accounts receivable securitization received as cash. + References No definition available. + Details
Name: | duk_Percentofproceedsreceivedascash
Namespace Prefix: | duk_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Definition Percent of proceeds from accounts receivable securitization received as subordinated note. + References No definition available. + Details
Name: | duk_Percentofproceedsreceivedassubordinatednote
Namespace Prefix: | duk_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Definition Minimum equity Balance required by Cinergy Receivables + References No definition available. + Details
Name: | duk_ReceivablesToMaintainMinimumEquityBalance
Namespace Prefix: | duk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition Date the credit facility terminates, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
Name: | us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=28200181&loc=SL6759159-111685 + Details
Name: | us-gaap_VariableInterestEntityOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration