Income Taxes (Effective Tax Rates) (Details) - USD ($) $ in Millions	12 Months Ended			96 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2022
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 35%	$ 1,448	$ 1,447	$ 1,328
State income tax, net of federal income tax effect	109	59	66
Tax differential on foreign earnings	(27)	(110)	(49)
AFUDC equity income	(58)	(47)	(55)
Renewable energy production tax credits	(72)	(67)	(62)
International Tax Dividend		373
Audit Adjustment	(22)
Tax true-up	2
Other items, net	(54)	14	(23)
Income tax expense (benefit) from continuing operations	$ 1,326	$ 1,669	$ 1,205
Effective tax rate	32.10%	40.40%	31.80%
Foreign Earnings of Subsidiaries
Undistributed Earnings of Foreign Subsidiaries	$ 250
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Foreign Subsidiaries	12
Foreign Jurisdictions [Member] | Merger of Subsidiaries [Member]
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 (benefit) from continuing operations		$ (57)
Duke Energy Carolinas [Member]
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 35%	598	581	$ 549
State income tax, net of federal income tax effect	46	17	56
AFUDC equity income	(34)	(32)	(32)
Tax true-up	2
Other items, net	15	22	21
Income tax expense (benefit) from continuing operations	$ 627	$ 588	$ 594
Effective tax rate	36.70%	35.40%	37.80%
Progress Energy [Member]
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 35%	$ 555	$ 497	$ 361
State income tax, net of federal income tax effect	18	49	31
AFUDC equity income	(19)	(9)	(18)
Renewable energy production tax credits	(1)
Audit Adjustment	(23)
Tax true-up	(3)
Other items, net	(5)	3	(1)
Income tax expense (benefit) from continuing operations	$ 522	$ 540	$ 373
Effective tax rate	32.90%	38.00%	36.20%
Duke Energy Progress [Member]
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 35%	$ 302	$ 263	$ 276
State income tax, net of federal income tax effect	15	25	31
AFUDC equity income	(17)	(9)	(15)
Audit Adjustment	1
Tax true-up	(4)
Other items, net	(3)	6	(4)
Income tax expense (benefit) from continuing operations	$ 294	$ 285	$ 288
Effective tax rate	34.20%	37.90%	36.50%
Duke Energy Florida [Member]
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 35%	$ 330	$ 314	$ 188
State income tax, net of federal income tax effect	33	34	20
AFUDC equity income	(3)		(3)
Audit Adjustment	(24)
Tax true-up	2
Other items, net	4	1	8
Income tax expense (benefit) from continuing operations	$ 342	$ 349	$ 213
Effective tax rate	36.30%	38.90%	39.60%
Duke Energy Ohio [Member]
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 35%	$ 81	$ 39	$ 39
State income tax, net of federal income tax effect	2	3	2
AFUDC equity income	(1)	(1)
Tax true-up	(5)
Other items, net	4	2	2
Income tax expense (benefit) from continuing operations	$ 81	$ 43	$ 43
Effective tax rate	35.20%	38.90%	39.10%
Duke Energy Indiana [Member]
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 35%	$ 168	$ 195	$ 203
State income tax, net of federal income tax effect	2	10	23
AFUDC equity income	(4)	(5)	(5)
Tax true-up	(9)
Other items, net	6	(3)	2
Income tax expense (benefit) from continuing operations	$ 163	$ 197	$ 223
Effective tax rate	34.00%	35.50%	38.40%
International Energy [Member]
Foreign Earnings of Subsidiaries
Foreign Earnings Repatriated	$ 1,500
Scenario, Forecast [Member] | International Energy [Member]
Foreign Earnings of Subsidiaries
Foreign Earnings Repatriated				$ 2,700