Variable Interest Entities (Narrative) (Details) $ in Millions	3 Months Ended
Mar. 31, 2016 USD ($)
Cinergy Receivables [Member]
Variable Interest Entities [Line Items]
Minimum equity balance required by Cinergy Receivables	$ 3
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 American Transmission Company [Member] \| Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	50.00%
Atlantic Coast Pipeline [Member] \| Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	40.00%
Sabal Trail Transmission Pipeline [Member] \| Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	7.50%
OVEC [Member] \| Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	9.00%
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 Indiana [Member] \| Cinergy Receivables [Member]
Variable Interest Entities [Line Items]
Fixed interest rate added to LIBOR to compute variable rate	1.00%

Percent of proceeds from accounts receivable securitization received as cash.

No definition available.

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- Definition

Percent of proceeds from accounts receivable securitization received as subordinated note.

+ References

No definition available.

+ Details

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

- Definition

Minimum equity Balance required by Cinergy Receivables

+ References

No definition available.

+ Details

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Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

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- 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=52262685&loc=SL6759159-111685

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Details

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- Details

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- Details

Name:	us-gaap_ConsolidationItemsAxis=duk_DukeAmericanTransmissionCompanyMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
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- Details

Name:	us-gaap_ConsolidationItemsAxis=duk_AtlanticCoastPipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=duk_SabalTrailTransmissionPipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=duk_OVECMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	dei_LegalEntityAxis=duk_DukeEnergyOhioMember
Namespace Prefix:
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- Details

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