Debt and Credit Facilities (Narrative) (Details)	Mar. 31, 2021 USD ($) tranche	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Debt issuances	$ 350,000,000
Number of tranches \| tranche	2
Current maturities of long-term debt	$ 5,586,000,000	$ 4,238,000,000
Duke Energy Carolinas
Debt Instrument [Line Items]
Debt issuances	0
Current maturities of long-term debt	507,000,000	$ 506,000,000
Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Debt issuances	1,000,000,000
First Tranche \| Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Debt issuances	$ 550,000,000
Stated rate	2.55%
Second Tranche \| Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Debt issuances	$ 450,000,000
Stated rate	3.45%
Bonds maturing June 2021, 3.900% interest rate \| Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Stated rate	3.90%
Current maturities of long-term debt	$ 500,000,000

Number of Tranches

No definition available.

Name:	duk_NumberOfTranches
Namespace Prefix:	duk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19,20)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_FirstMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=duk_FirstTrancheMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=duk_SecondTrancheMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=duk_BondsMaturingJune20213.900CouponMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: