v2.4.0.6

Variable Interest Entities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		3 Months Ended						3 Months Ended
	Mar. 31, 2013	Dec. 31, 2010 DukeNet And Alinda Capital Partners LLC Ownership In The New Joint Venture [Member]	Mar. 31, 2013 Cinergy Receivables [Member]	Mar. 31, 2013 Cinergy Receivables [Member] Minimum [Member]	Mar. 31, 2013 Cinergy Receivables [Member] Maximum [Member]	Mar. 31, 2013 CinCap V [Member]	Mar. 31, 2013 Duke Energy Carolinas [Member] DERF [Member] Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2012 Progress Energy [Member] FPC Capital I Trust [Member]	Mar. 31, 2013 Duke Energy Ohio [Member] Cinergy Receivables [Member]	Mar. 31, 2013 Duke Energy Ohio [Member] Other VIEs [Member]	Mar. 31, 2013 Duke Energy Indiana [Member] Cinergy Receivables [Member]
Variable Interest Entity [Line Items]
Proceeds received for sale of receivables, portion received as note payable			25.00%
Minimum Equity Balance required by Cinergy Receivables			$ 3
Subordinated retained interest limitation of the total proceeds				10.00%	20.00%
Secured credit facility of variable interest entities							300
Fixed rate used when selling receivables									1.00%		1.00%
Equity ownership interest rate		50.00%
Senior secured credit facility		150
Line of credit facility, expiration date	Nov. 01, 2016		Nov. 01, 2013				Aug. 01, 2014
Ownership interest in OVEC										9.00%
CinCap purchased power contract expiration						2016
Debt instrument, face amount								$ 300

X

- Definition

Duke Energy's expiration date for purchased power contract with Central Maine Power Company.

+ References

No definition available.

+ Details

Name:	duk_CincapPurchasedPowerContractExpiration
Namespace Prefix:	duk_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Duke Energy's ownership interest in OVEC.

+ References

No definition available.

+ Details

Name:	duk_OvecOwnershipInterest
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Proceeds Received For Sale Of Receivables Portion Received As Note Payable

+ References

No definition available.

+ Details

Name:	duk_ProceedsReceivedForSaleOfReceivablesPortionReceivedAsNotePayable
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- 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

X

- Definition

Sale of Receivables, Fixed Rate Used in Calculation

+ References

No definition available.

+ Details

Name:	duk_SaleOfReceivablesFixedRateUsedInCalculation
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Secured Credit Facility Of Vie

+ References

No definition available.

+ Details

Name:	duk_SecuredCreditFacilityOfVie
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Subordinated Retained Interest Limitation Of The Total Proceeds

+ References

No definition available.

+ Details

Name:	duk_SubordinatedRetainedInterestLimitationOfTotalProceeds
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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

X

- 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

X

- Definition

Carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.

+ 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 210.5-02.22)

-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 22

-Article 5

+ Details

Name:	us-gaap_SeniorLongTermNotes
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

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