Income Taxes (Effective Tax Rates) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 21%		$ 790	$ 176	$ 860
State income tax, net of federal income tax effect		1	(80)	(22)
Amortization of excess deferred income tax		(438)	(276)	(121)
AFUDC equity income		(34)	(48)	(52)
AFUDC equity depreciation		35	103	34
Noncontrolling Interests		72	62
Renewable energy PTCs		(100)	(110)	(120)
Other tax credits		(30)	(37)	(23)
Tax true up			(12)	(64)
Valuation allowance	$ (85)	(85)
Other items, net		(19)	(14)	27
Income tax expense from continuing operations		$ 192	$ (236)	$ 519
Effective tax rate		5.10%	(28.10%)	12.70%
Federal capital gain	$ 426
Duke Energy Carolinas
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 21%		$ 291	$ 219	$ 360
State income tax, net of federal income tax effect		(44)	(40)	(19)
Amortization of excess deferred income tax		(184)	(82)	(29)
AFUDC equity income		(14)	(13)	(9)
AFUDC equity depreciation		18	19	19
Other tax credits		(12)	(13)	(11)
Tax true up			(3)	(9)
Other items, net		(4)	1	9
Income tax expense from continuing operations		$ 51	$ 88	$ 311
Effective tax rate		3.70%	8.40%	18.10%
Progress Energy
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 21%		$ 384	$ 243	$ 332
State income tax, net of federal income tax effect		34	4	8
Amortization of excess deferred income tax		(174)	(118)	(64)
AFUDC equity income		(11)	(9)	(14)
AFUDC equity depreciation		10	10	10
Other tax credits		(11)	(16)	(9)
Tax true up			1	(8)
Other items, net		(5)	(2)	(2)
Income tax expense from continuing operations		$ 227	$ 113	$ 253
Effective tax rate		12.40%	9.70%	16.00%
Duke Energy Progress
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 21%		$ 224	$ 80	$ 202
State income tax, net of federal income tax effect		(14)	(25)	(17)
Amortization of excess deferred income tax		(120)	(68)	(10)
AFUDC equity income		(7)	(6)	(13)
AFUDC equity depreciation		5	5	5
Other tax credits		(8)	(14)	(7)
Tax true up			(5)	(3)
Other items, net		(5)	(3)
Income tax expense from continuing operations		$ 75	$ (36)	$ 157
Effective tax rate		7.00%	(9.50%)	16.30%
Duke Energy Florida
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 21%		$ 194	$ 204	$ 178
State income tax, net of federal income tax effect		47	39	35
Amortization of excess deferred income tax		(54)	(49)	(54)
AFUDC equity income		(3)	(3)	(1)
AFUDC equity depreciation		5	5	5
Other tax credits		(3)	(2)	(2)
Tax true up			5	(5)
Other items, net		1	(1)	(1)
Income tax expense from continuing operations		$ 187	$ 198	$ 155
Effective tax rate		20.20%	20.40%	18.30%
Duke Energy Ohio
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 21%		$ 49	$ 62	$ 59
State income tax, net of federal income tax effect		2	2	3
Amortization of excess deferred income tax		(22)	(20)	(12)
AFUDC equity income		(2)	(2)	(3)
AFUDC equity depreciation		2	1	1
Other tax credits		(1)	(1)	(1)
Tax true up				(7)
Other items, net		2	1
Income tax expense from continuing operations		$ 30	$ 43	$ 40
Effective tax rate		12.80%	14.60%	14.30%
Duke Energy Indiana
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 21%		$ 123	$ 103	$ 120
State income tax, net of federal income tax effect		18	19	22
Amortization of excess deferred income tax		(34)	(36)	(6)
AFUDC equity income		(4)	(4)	(3)
AFUDC equity depreciation		5	4	4
Other tax credits		(2)	(3)	(1)
Tax true up			(1)	(1)
Other items, net		1	2	(1)
Income tax expense from continuing operations		$ 107	$ 84	$ 134
Effective tax rate		18.20%	17.10%	23.50%
Piedmont
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 21%		$ 71	$ 61	$ 51
State income tax, net of federal income tax effect		(8)	(12)	2
Amortization of excess deferred income tax		(25)	(21)	(10)
AFUDC equity income		(4)	(10)
Other tax credits		(4)	(2)	(1)
Tax true up			1
Other items, net			1	1
Income tax expense from continuing operations		$ 30	$ 18	$ 43
Effective tax rate		8.80%	6.20%	17.60%