Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 5,077	$ 3,141
Other debt obligations
Debt Instrument [Line Items]
Current maturities of long-term debt	359
Duke Energy Progress
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,006	1,006
Duke Energy Progress | Unsecured Debt | Debt maturing December 2020, floating interest rate
Debt Instrument [Line Items]
Interest Rate	2.292%
Current maturities of long-term debt	$ 700
Duke Energy Progress | First Mortgage Bonds | Bonds maturing September 2020, floating interest rate
Debt Instrument [Line Items]
Interest Rate	1.076%
Current maturities of long-term debt	$ 300
Progress Energy
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,828	1,577
Progress Energy | Unsecured Debt | Debt maturing January 2021, 4.400% interest rate
Debt Instrument [Line Items]
Interest Rate	4.40%
Current maturities of long-term debt	$ 500
Duke Energy Florida
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 322	571
Duke Energy Florida | First Mortgage Bonds | Bonds maturing April 2020, 4.550% interest rate
Debt Instrument [Line Items]
Interest Rate	4.55%
Current maturities of long-term debt	$ 250
Duke Energy Carolinas
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 457	458
Duke Energy Carolinas | First Mortgage Bonds | Bonds maturing June 2020, 4.300% interest rate
Debt Instrument [Line Items]
Interest Rate	4.30%
Current maturities of long-term debt	$ 450
Duke Energy Indiana
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 503	$ 503
Duke Energy Indiana | First Mortgage Bonds | Bonds maturing July 2020, 3.750% interest rate
Debt Instrument [Line Items]
Interest Rate	3.75%
Current maturities of long-term debt	$ 500
Duke Energy (Parent) | Unsecured Debt | Debt maturing June 2020, 2.100% interest rate
Debt Instrument [Line Items]
Interest Rate	2.10%
Current maturities of long-term debt	$ 330
Duke Energy (Parent) | Unsecured Debt | Debt maturing March 2021, floating interest rate
Debt Instrument [Line Items]
Interest Rate	1.40%
Current maturities of long-term debt	$ 1,688