Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($)	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Debt Instrument [Line Items]
Debt issuances	$ 3,138,000,000
Repayments of long-term debt	292,000,000	$ 1,201,000,000
Duke Energy Carolinas
Debt Instrument [Line Items]
Debt issuances	900,000,000
Repayments of long-term debt	2,000,000	1,000,000
Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Repayments of long-term debt	450,000,000
Duke Energy Indiana
Debt Instrument [Line Items]
Debt issuances	550,000,000
Repayments of long-term debt		$ 60,000,000
Duke Energy Indiana \| First Mortgage Bonds
Debt Instrument [Line Items]
Repayments of long-term debt	$ 500,000,000
Unsecured Debt \| March 2020 1.400% Due March 2021
Debt Instrument [Line Items]
Interest Rate	1.40%
Debt issuances	$ 1,688,000,000
First Mortgage Bonds \| January 2020 2.450% Due 2030
Debt Instrument [Line Items]
Interest Rate	2.45%
Debt issuances	$ 500,000,000
First Mortgage Bonds \| January 2020 3.20% Due 2049
Debt Instrument [Line Items]
Interest Rate	3.20%
Debt issuances	$ 400,000,000
First Mortgage Bonds \| March 2020 2.750% Due 2050
Debt Instrument [Line Items]
Interest Rate	2.75%
Debt issuances	$ 550,000,000
First Mortgage Bonds \| Duke Energy Carolinas \| January 2020 2.450% Due 2030
Debt Instrument [Line Items]
Debt issuances	500,000,000
First Mortgage Bonds \| Duke Energy Carolinas \| January 2020 3.20% Due 2049
Debt Instrument [Line Items]
Debt issuances	400,000,000
First Mortgage Bonds \| Duke Energy Indiana \| March 2020 2.750% Due 2050
Debt Instrument [Line Items]
Debt issuances	550,000,000
Duke Energy (Parent) \| Duke Energy (Parent)
Debt Instrument [Line Items]
Debt issuances	1,688,000,000
Duke Energy (Parent) \| Unsecured Debt \| Duke Energy (Parent) \| March 2020 1.400% Due March 2021
Debt Instrument [Line Items]
Debt issuances	$ 1,688,000,000

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

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=114775744&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

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+ 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
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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
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-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

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