Derivatives and Hedging (Derivative Instruments That Contain Credit-Risk Related Contingent Features and Cash Collateral) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value of derivatives in a net liability position	$ 24	$ 79
Fair value of collateral already posted	0	0
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	24	79
Duke Energy Carolinas
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value of derivatives in a net liability position	9	35
Fair value of collateral already posted	0	0
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	9	35
Progress Energy
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value of derivatives in a net liability position	14	44
Fair value of collateral already posted	0	0
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	14	44
Duke Energy Progress
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value of derivatives in a net liability position	14	44
Fair value of collateral already posted	0	0
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	$ 14	$ 44

The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624258-113959

+ Details

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

- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624258-113959

+ Details

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

- Definition

The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624258-113959

+ Details

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

- References

No definition available.

+ Details

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

- Details

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

- Details

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

- Details

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