Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 5,586	$ 4,238
Other debt obligations
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 723
Duke Energy (Parent) | Unsecured Debt | Debt maturing May 2021, floating interest rate
Debt Instrument [Line Items]
Interest Rate	0.698%
Current maturities of long-term debt	$ 500
Duke Energy (Parent) | Unsecured Debt | Debt maturing September 2021, 3.550% interest rate
Debt Instrument [Line Items]
Interest Rate	3.55%
Current maturities of long-term debt	$ 500
Duke Energy (Parent) | Unsecured Debt | Debt maturing September 2021, 1.800% interest rate
Debt Instrument [Line Items]
Interest Rate	1.80%
Current maturities of long-term debt	$ 750
Duke Energy (Parent) | Unsecured Debt | Debt Maturing March 2022, 3.227% interest rate
Debt Instrument [Line Items]
Interest Rate	3.227%
Current maturities of long-term debt	$ 300
Duke Energy (Parent) | Unsecured Debt | Debt Maturing March 2022 0.871%, floating interest rate
Debt Instrument [Line Items]
Interest Rate	0.827%
Current maturities of long-term debt	$ 300
Piedmont
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 160	160
Piedmont | Unsecured Debt | Debt maturing June 2021, 4.240% interest rate
Debt Instrument [Line Items]
Interest Rate	4.24%
Current maturities of long-term debt	$ 160
Duke Energy Florida
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 824	823
Duke Energy Florida | Unsecured Debt | Debt Maturing November 2021, 0.482% interest rate
Debt Instrument [Line Items]
Interest Rate	0.441%
Current maturities of long-term debt	$ 200
Duke Energy Florida | First Mortgage Bonds | Bonds maturing August 2021, 3.100% interest rate
Debt Instrument [Line Items]
Interest Rate	3.10%
Current maturities of long-term debt	$ 300
Duke Energy Carolinas
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 507	506
Duke Energy Carolinas | First Mortgage Bonds | Bonds maturing June 2021, 3.900% interest rate
Debt Instrument [Line Items]
Interest Rate	3.90%
Current maturities of long-term debt	$ 500
Duke Energy Progress
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,302	603
Duke Energy Progress | Unsecured Debt | Debt Maturing February 2022, 0.400%, floating interest rate
Debt Instrument [Line Items]
Interest Rate	0.369%
Current maturities of long-term debt	$ 700
Duke Energy Progress | First Mortgage Bonds | Debt maturing September 2021, 3.000% interest rate
Debt Instrument [Line Items]
Interest Rate	3.00%
Current maturities of long-term debt	$ 500
Duke Energy Progress | First Mortgage Bonds | Debt maturing September 2021, 8.625% interest rate
Debt Instrument [Line Items]
Interest Rate	8.625%
Current maturities of long-term debt	$ 100
Duke Energy Indiana
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 123	$ 70
Duke Energy Indiana | First Mortgage Bonds | Debt Maturing January 2022, 8.850% interest rate
Debt Instrument [Line Items]
Interest Rate	8.85%
Current maturities of long-term debt	$ 53