Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current income taxes
Federal	$ (2)	$ (281)	$ (299)
State	2	(9)	10
Foreign	2	1	2
Total current income taxes	2	(289)	(287)
Deferred income taxes
Federal	199	155	855
State	(1)	(92)	(38)
Total deferred income taxes	198	63	817
ITC amortization	(8)	(10)	(11)
Income tax expense from continuing operations	192	(236)	519
Tax expense from discontinued operations		2	(2)
Total income tax expense included in Consolidated Statements of Operations	192	(234)	517
Net operating loss carry forward	150	79	775
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Domestic	3,720	826	4,053
Foreign	44	13	44
Income from continuing operations before income taxes	3,764	839	4,097
Duke Energy Carolinas
Current income taxes
Federal	241	314	164
State	23	35	13
Total current income taxes	264	349	177
Deferred income taxes
Federal	(130)	(171)	175
State	(79)	(86)	(37)
Total deferred income taxes	(209)	(257)	138
ITC amortization	(4)	(4)	(4)
Income tax expense from continuing operations	51	88	311
Total income tax expense included in Consolidated Statements of Operations	51	88	311
Net operating loss carry forward	32	20	8
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Income from continuing operations before income taxes	1,387	1,044	1,714
Progress Energy
Current income taxes
Federal	(15)	280	(173)
State	(4)	29	(7)
Total current income taxes	(19)	309	(180)
Deferred income taxes
Federal	203	(167)	422
State	47	(24)	17
Total deferred income taxes	250	(191)	439
ITC amortization	(4)	(5)	(6)
Income tax expense from continuing operations	227	113	253
Total income tax expense included in Consolidated Statements of Operations	227	113	253
Net operating loss carry forward	95	39	243
Duke Energy Progress
Current income taxes
Federal	113	181	(36)
State	8	17	(3)
Total current income taxes	121	198	(39)
Deferred income taxes
Federal	(16)	(180)	220
State	(26)	(49)	(18)
Total deferred income taxes	(42)	(229)	202
ITC amortization	(4)	(5)	(6)
Income tax expense from continuing operations	75	(36)	157
Total income tax expense included in Consolidated Statements of Operations	75	(36)	157
Net operating loss carry forward	14	3	35
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Income from continuing operations before income taxes	1,066	379	962
Duke Energy Florida
Current income taxes
Federal	(75)	148	(43)
State	(17)	24	18
Total current income taxes	(92)	172	(25)
Deferred income taxes
Federal	202	1	153
State	77	25	27
Total deferred income taxes	279	26	180
Income tax expense from continuing operations	187	198	155
Total income tax expense included in Consolidated Statements of Operations	187	198	155
Net operating loss carry forward	64	30	152
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Income from continuing operations before income taxes	925	969	847
Duke Energy Ohio
Current income taxes
Federal	(8)	10	(41)
State	(2)	1	(1)
Total current income taxes	(10)	11	(42)
Deferred income taxes
Federal	35	30	77
State	5	2	5
Total deferred income taxes	40	32	82
Income tax expense from continuing operations	30	43	40
Total income tax expense included in Consolidated Statements of Operations	30	43	40
Net operating loss carry forward	2		25
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Income from continuing operations before income taxes	234	295	279
Duke Energy Indiana
Current income taxes
Federal	65	48	(23)
State	7	7	1
Total current income taxes	72	55	(22)
Deferred income taxes
Federal	19	12	128
State	16	17	28
Total deferred income taxes	35	29	156
Income tax expense from continuing operations	107	84	134
Total income tax expense included in Consolidated Statements of Operations	107	84	134
Net operating loss carry forward	8	8	60
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Income from continuing operations before income taxes	588	492	570
Piedmont
Current income taxes
Federal	23	(27)	(92)
State	3	(8)	(1)
Total current income taxes	26	(35)	(93)
Deferred income taxes
Federal	17	60	133
State	(13)	(7)	3
Total deferred income taxes	4	53	136
Income tax expense from continuing operations	30	18	43
Total income tax expense included in Consolidated Statements of Operations	30	18	43
Net operating loss carry forward	3	11	90
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Income from continuing operations before income taxes	$ 340	$ 291	$ 245