Goodwill and Intangible Assets (Schedule of Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	$ 271	$ 277
Accumulated amortization	(45)	(35)
Total intangible assets, net	226	242
Amortization expense	6	5	$ 6
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2017	5
2018	5
2019	5
2020	5
2021	5
Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	19	20
Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	125	116
Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	24	24
Accumulated amortization	(17)	(16)
Renewable Operating and Development Projects [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	97	115
Accumulated amortization	(23)	(18)
Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	6	2
Accumulated amortization	(5)	(1)
Duke Energy Carolinas [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	37	31
Total intangible assets, net	37	31
Duke Energy Carolinas [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	1	1
Duke Energy Carolinas [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	36	30
Progress Energy [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	90	86
Total intangible assets, net	90	86
Progress Energy [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	6	6
Progress Energy [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	84	80
Duke Energy Progress [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	86	82
Total intangible assets, net	86	82
Duke Energy Progress [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	2	2
Duke Energy Progress [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	84	80
Duke Energy Florida [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	4	4
Total intangible assets, net	4	4
Duke Energy Florida [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	4	4
Duke Energy Ohio [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	4	5
Total intangible assets, net	4	5
Amortization expense			2
Duke Energy Ohio [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	0
Duke Energy Ohio [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	4	5
Duke Energy Ohio [Member] | Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	0
Accumulated amortization	0
Duke Energy Indiana [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	37	38
Accumulated amortization	(17)	(16)
Total intangible assets, net	20	22
Amortization expense	1	1	$ 1
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2017	2
2018	2
2019	2
2020	2
2021	2
Duke Energy Indiana [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	13	14
Duke Energy Indiana [Member] | Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	24	24
Accumulated amortization	$ (17)	$ (16)