Revenue (Reserve for Credit Losses for Trade and Other Receivables) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 122	$ 146
Cumulative Change in Accounting Principle	140	147
Write-Offs	(23)	(21)
Credit Loss Expense	24	17
Other Adjustments	17	5
Ending balance	140	147
Duke Energy Carolinas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	42	23
Cumulative Change in Accounting Principle	52	34
Write-Offs	(9)	(8)
Credit Loss Expense	5	10
Other Adjustments	14	9
Ending balance	52	34
Progress Energy
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	36	37
Cumulative Change in Accounting Principle	51	37
Write-Offs	(10)	(10)
Credit Loss Expense	12	7
Other Adjustments	13	3
Ending balance	51	37
Duke Energy Progress
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	21	23
Cumulative Change in Accounting Principle	31	23
Write-Offs	(2)	(5)
Credit Loss Expense	4	2
Other Adjustments	8	3
Ending balance	31	23
Duke Energy Florida
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	16	14
Cumulative Change in Accounting Principle	21	15
Write-Offs	(8)	(5)
Credit Loss Expense	8	5
Other Adjustments	5	1
Ending balance	21	15
Duke Energy Ohio
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4	4
Cumulative Change in Accounting Principle	4	4
Ending balance	4	4
Duke Energy Indiana
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3	3
Cumulative Change in Accounting Principle	3	3
Ending balance	3	3
Piedmont
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	15	12
Cumulative Change in Accounting Principle	17	14
Write-Offs	(1)	(1)
Credit Loss Expense	3	3
Ending balance	$ 17	$ 14