Revenue (Reserve for Credit Losses for Trade and Other Receivables) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 146	$ 76
Cumulative Change in Accounting Principle	147	89
Write-Offs	(21)	(10)
Credit Loss Expense	17	18
Other Adjustments	5
Ending balance	147	89
Duke Energy Carolinas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	23	10
Cumulative Change in Accounting Principle	34	11
Write-Offs	(8)	(3)
Credit Loss Expense	10	3
Other Adjustments	9
Ending balance	34	11
Progress Energy
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	37	16
Cumulative Change in Accounting Principle	37	20
Write-Offs	(10)	(4)
Credit Loss Expense	7	6
Other Adjustments	3
Ending balance	37	20
Duke Energy Progress
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	23	8
Cumulative Change in Accounting Principle	23	9
Write-Offs	(5)	(2)
Credit Loss Expense	2	2
Other Adjustments	3
Ending balance	23	9
Duke Energy Florida
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	14	7
Cumulative Change in Accounting Principle	15	11
Write-Offs	(5)	(2)
Credit Loss Expense	5	5
Other Adjustments	1
Ending balance	15	11
Duke Energy Ohio
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4	4
Cumulative Change in Accounting Principle	4	5
Credit Loss Expense		1
Ending balance	4	5
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	12	6
Cumulative Change in Accounting Principle	14	9
Write-Offs	(1)	(1)
Credit Loss Expense	3	3
Ending balance	$ 14	9
Cumulative Change in Accounting Principle
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		5
Cumulative Change in Accounting Principle		5
Cumulative Change in Accounting Principle | Duke Energy Carolinas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Cumulative Change in Accounting Principle		1
Cumulative Change in Accounting Principle | Progress Energy
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		2
Cumulative Change in Accounting Principle		2
Cumulative Change in Accounting Principle | Duke Energy Progress
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Cumulative Change in Accounting Principle		1
Cumulative Change in Accounting Principle | Duke Energy Florida
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Cumulative Change in Accounting Principle		1
Cumulative Change in Accounting Principle | Piedmont
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Cumulative Change in Accounting Principle		$ 1