Goodwill and Intangible Assets (Schedule of Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	$ 343	$ 317
Accumulated amortization	(58)	(54)
Total intangible assets, net	285	263
Amortization expense	4	6	$ 13
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2016	8
2017	8
2018	8
2019	7
2020	7
Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	20	23
Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	116	97
Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	24	24
Accumulated amortization	(16)	(15)
Wind Development Rights [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	115	97
Accumulated amortization	(18)	(14)
Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	68	76
Accumulated amortization	(24)	(25)
Duke Energy Carolinas [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	31	26
Total intangible assets, net	31	26
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	30	25
Progress Energy [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	86	76
Total intangible assets, net	86	76
Progress Energy [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	6	7
Progress Energy [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	80	69
Duke Energy Progress [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	82	72
Total intangible assets, net	82	72
Duke Energy Progress [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	2	3
Duke Energy Progress [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	80	69
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	5	3
Total intangible assets, net	5	3
Amortization expense		2	8
Duke Energy Ohio [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	5	3
Duke Energy Indiana [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	38	40
Accumulated amortization	(16)	(15)
Total intangible assets, net	22	25
Amortization expense	1	1	$ 1
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2016	2
2017	2
2018	2
2019	2
2020	2
Duke Energy Indiana [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	14	16
Duke Energy Indiana [Member] | Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	24	24
Accumulated amortization	$ (16)	$ (15)