Employee Benefit Plans (Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive income	[1]	$ (7)	$ (6)	$ (9)
Progress Energy
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive income		(1)	1	$ (2)
Pension Plan | Qualified Plan
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(261)	(62)
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax expense		1	2
Amortization of prior year actuarial gain		(8)	(11)
Amortization of prior year service credit		1	1
Net amount recognized in accumulated other comprehensive income		(6)	(8)
Pension Plan | Duke Energy Carolinas | Qualified Plan
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(57)	(39)
Pension Plan | Progress Energy | Qualified Plan
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(128)	(26)
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax expense			1
Amortization of prior year actuarial gain		(1)	(1)
Net amount recognized in accumulated other comprehensive income		(1)
Pension Plan | Duke Energy Progress | Qualified Plan
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(31)	(30)
Pension Plan | Duke Energy Florida | Qualified Plan
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(97)	4
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax expense			1
Amortization of prior year actuarial gain			(3)
Net amount recognized in accumulated other comprehensive income			(2)
Pension Plan | Duke Energy Ohio | Qualified Plan
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(17)	(2)
Pension Plan | Duke Energy Indiana | Qualified Plan
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(19)	5
Pension Plan | Piedmont | Qualified Plan
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(5)	(1)
Other Post-Retirement Benefit Plans
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(15)	9
Regulatory liabilities, net increase		23	(10)
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Amortization of prior year actuarial gain		(1)
Amortization of prior year service credit			1
Net amount recognized in accumulated other comprehensive income		(1)	1
Other Post-Retirement Benefit Plans | Duke Energy Carolinas
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory liabilities, net increase		12	(7)
Other Post-Retirement Benefit Plans | Progress Energy
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(18)	9
Other Post-Retirement Benefit Plans | Duke Energy Progress
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(9)	6
Other Post-Retirement Benefit Plans | Duke Energy Florida
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(9)	3
Other Post-Retirement Benefit Plans | Duke Energy Ohio
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		4
Regulatory liabilities, net increase		4
Other Post-Retirement Benefit Plans | Duke Energy Indiana
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net decrease		(4)	(4)
Regulatory liabilities, net increase		1	$ (1)
Other Post-Retirement Benefit Plans | Piedmont
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory liabilities, net increase		$ 2

[1] Net of income tax impacts of approximately $17 million and $35 million for the years ended December 31, 2021, and 2020, respectively. Tax impacts are immaterial for other periods presented.