Equity Method Investment, Maximum Loss Exposure, Amount

No definition available.

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

- Definition

Estimated capital cost of new project

+ References

No definition available.

+ Details

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

- Definition

Maximum potential percentage of future payments the guarantor could be required to make under the guarantee in relationship to the total borrowings by the joint venture on the credit facility.

+ References

No definition available.

+ Details

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

- Definition

Long-term Purchases, Supply Contract, Term

+ References

No definition available.

+ Details

Name:	duk_LongtermPurchasesSupplyContractTerm
Namespace Prefix:	duk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 35
-Paragraph 32
-URI http://asc.fasb.org/extlink&oid=118954474&loc=d3e32787-111569

+ Details

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

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_EquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-URI http://asc.fasb.org/extlink&oid=115995737&loc=d3e659983-123033

+ Details

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

- Definition

Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
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

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

- Definition

Period end amount of total net PPE.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=duk_AtlanticCoastPipelineACPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=duk_DominionResourcesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=duk_SouthernCompanyGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=duk_ConstitutionPipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=duk_WilliamsPartnersL.P.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	dei_LegalEntityAxis=duk_DukeEnergyProgressMember
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_PropertyPlantAndEquipmentByTypeAxis=duk_GenerationFacilitiesEvaluatedForRetirementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_FinancialGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=duk_AtlanticCoastPipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Regulatory Matters (Other Regulatory Matters Narrative) (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Sep. 02, 2014	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Public Utilities, General Disclosures [Line Items]
Investments in equity method unconsolidated affiliates		$ 1,936	$ 1,936	$ 1,409	$ 1,175
Remaining net book value		102,127	102,127	91,694
Atlantic Coast Pipeline (ACP)
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	47.00%
Supply contract, term	20 years
Estimated capital cost		8,000	8,000
Investments in equity method unconsolidated affiliates		1,200	1,200
Maximum loss exposure, amount		$ 827	$ 827
Atlantic Coast Pipeline (ACP) \| Dominion Resources
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	48.00%
Atlantic Coast Pipeline (ACP) \| Southern Company Gas
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	5.00%
Constitution
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage		24.00%	24.00%
OTTI impairment loss		$ 25
Constitution \| Williams Partners L.P.
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage		41.00%	41.00%
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Remaining net book value		$ 32,397	$ 32,397	29,245
Duke Energy Carolinas \| Atlantic Coast Pipeline (ACP)
Public Utilities, General Disclosures [Line Items]
Long-term purchase commitment term	20 years
Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Remaining net book value		22,934	22,934	20,398
Duke Energy Progress \| Atlantic Coast Pipeline (ACP)
Public Utilities, General Disclosures [Line Items]
Long-term purchase commitment term	20 years
Piedmont
Public Utilities, General Disclosures [Line Items]
Investments in equity method unconsolidated affiliates		83	83	64
Remaining net book value		6,765	6,765	$ 5,911
Piedmont \| Atlantic Coast Pipeline (ACP)
Public Utilities, General Disclosures [Line Items]
Long-term purchase commitment term	20 years
Generation Facilities Evaluated For Retirement \| Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Remaining net book value		721	721
Generation Facilities Evaluated For Retirement \| Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Remaining net book value		$ 1,200	$ 1,200
Financial guarantee \| ACP
Public Utilities, General Disclosures [Line Items]
Maximum exposure percentage			47.00%