Equity Method Investment Ownership Percentage Sold

No definition available.

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

- Definition

EquityMethodInvestmentVotingRightsOwnershipPercentage

+ References

No definition available.

+ Details

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

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

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

- Definition

Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(10))
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(12))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21D
-URI http://asc.fasb.org/extlink&oid=98514028&loc=SL94080555-108585

+ Details

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

- 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 Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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

- Definition

The difference between the carrying value and the sale price of an investment. A gain would be recognized when the sale price of the investment is greater than the carrying value of the investment. This element refers to the Gain included in earnings and not to the cash proceeds of the sale.

+ References

No definition available.

+ Details

Name:	us-gaap_GainOnSaleOfInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(12))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(10))
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(13)(f))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

Name:	us-gaap_IncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21D
-URI http://asc.fasb.org/extlink&oid=98514028&loc=SL94080555-108585

+ Details

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

- Definition

The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

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

- Details

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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=duk_ElectricUtilitiesandInfrastructureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=duk_DukeAmericanTransmissionCoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=duk_PioneerTransmissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=duk_GasUtilitiesandInfrastructureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=duk_CommercialRenewablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=duk_SweetwaterIVVMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=duk_DSCornerstoneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=duk_OtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=duk_NationalMethanolCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=duk_PiedmontNaturalGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=duk_SouthStarMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Investments in Unconsolidated Affiliates (Narrative) (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2016	Dec. 31, 2015	Oct. 31, 2015	Oct. 03, 2016
Investments In Unconsolidated Affiliates [Line Items]
Distributions from equity investments		$ 13	$ 31		$ 104
Distributions from equity investments, return of capital		281	1		3
Income (Loss) from Equity Method Investments		119	(15)		69
Asset Impairment Charges		282	18		106
Atlantic Coast Pipeline [Member]
Investments In Unconsolidated Affiliates [Line Items]
Distributions from equity investments, return of capital		265
Electric Utilities and Infrastructure [Member]
Investments In Unconsolidated Affiliates [Line Items]
Income (Loss) from Equity Method Investments		$ 5	5		(2)
Electric Utilities and Infrastructure [Member] \| Duke American Transmission Co. [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage		50.00%
Electric Utilities and Infrastructure [Member] \| Pioneer Transmission [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage		50.00%
Gas Utilities and Infrastructure [Member]
Investments In Unconsolidated Affiliates [Line Items]
Income (Loss) from Equity Method Investments		$ 62	19		1
Gas Utilities and Infrastructure [Member] \| Atlantic Coast Pipeline [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage		47.00%
Commercial Renewables [Member]
Investments In Unconsolidated Affiliates [Line Items]
Income (Loss) from Equity Method Investments		$ (5)	(82)		(6)
Asset Impairment Charges			71
Commercial Renewables [Member] \| Variable Interest Entity, Not Primary Beneficiary [Member]
Investments In Unconsolidated Affiliates [Line Items]
Asset Impairment Charges			71
Commercial Renewables [Member] \| Sweetwater IV-V [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage		47.00%
Commercial Renewables [Member] \| DS Cornerstone [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage		50.00%
Other [Member]
Investments In Unconsolidated Affiliates [Line Items]
Income (Loss) from Equity Method Investments		$ 57	$ 43		$ 76
Other [Member] \| National Methanol Company [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage	25.00%	17.50%	25.00%
Board representation and voting rights, ownership percentage		25.00%
Piedmont Natural Gas [Member]
Investments In Unconsolidated Affiliates [Line Items]
Distributions from equity investments	$ 1	$ 4		$ 26		$ 25
Distributions from equity investments, return of capital	1	2		18		2
Income (Loss) from Equity Method Investments	$ 2	(6)		29		34
Asset Impairment Charges		$ 7
Piedmont Natural Gas [Member] \| SouthStar [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity Method Investment Ownership Percentage Sold							15.00%
Proceeds from Sale of Equity Method Investments				160
Gain on Sale of Investments				81
Income (Loss) from Equity Method Investments				$ 19		$ 19