Severance (Rollforward) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$ 11
Provision/adjustments	36
Cash reductions	(8)
Balance, end of period	39
Duke Energy Carolinas
Restructuring Reserve [Roll Forward]
Balance, beginning of period	2
Provision/adjustments	1
Cash reductions	(1)
Balance, end of period	2
Progress Energy
Restructuring Reserve [Roll Forward]
Balance, beginning of period	3
Provision/adjustments	1
Cash reductions	(2)
Balance, end of period	2
Duke Energy Progress
Restructuring Reserve [Roll Forward]
Balance, beginning of period	1
Provision/adjustments	1
Cash reductions	(1)
Balance, end of period	1
Duke Energy Florida
Restructuring Reserve [Roll Forward]
Balance, beginning of period	2
Cash reductions	(1)
Balance, end of period	1
Duke Energy Indiana
Restructuring Reserve [Roll Forward]
Balance, beginning of period	1
Cash reductions	$ (1)