Goodwill (Schedule of Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	$ 487	$ 595
Accumulated amortization	(109)	(223)
Total intangible assets, net	378	372
Amortization expense	13	14	10
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2014	43
2015	19
2016	17
2017	16
2018	16
Pretax impairment charge	399	666	335
Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	63	80
Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	82	18
Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	180	295
Accumulated amortization	(73)	(180)
Wind Development Rights [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	86	111
Accumulated amortization	(12)	(9)
Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	76	91
Accumulated amortization	(24)	(34)
Duke Energy Carolinas [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	17	14
Accumulated amortization	0	0
Total intangible assets, net	17	14
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Pretax impairment charge		31	12
Duke Energy Carolinas [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	1
Duke Energy Carolinas [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	16	14
Progress Energy [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	85	28
Accumulated amortization	0	0
Total intangible assets, net	85	28
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2014	4
2015	3
2016	2
2017	1
2018	1
Pretax impairment charge	380	200	3
Progress Energy [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	21	26
Progress Energy [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	64	2
Duke Energy Progress [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	67	5
Accumulated amortization	0	0
Total intangible assets, net	67	5
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2014	1
Pretax impairment charge	22	54	3
Duke Energy Progress [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	3	4
Duke Energy Progress [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	64	1
Duke Energy Florida [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	18	22
Accumulated amortization	0	0
Total intangible assets, net	18	22
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2014	3
2015	3
2016	2
2017	1
2018	1
Pretax impairment charge	358	146	0
Duke Energy Florida [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	18	22
Duke Energy Ohio [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	178	306
Accumulated amortization	(60)	(177)
Total intangible assets, net	118	129
Amortization expense	8	12	8
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2014	11
2015	9
2016	9
2017	9
2018	9
Pretax impairment charge	5	2	89
Duke Energy Ohio [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	20	24
Duke Energy Ohio [Member] | Emission Allowances [Member] | Commercial Power [Member]
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Pretax impairment charge			79
Duke Energy Ohio [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	2	0
Duke Energy Ohio [Member] | Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	156	272
Accumulated amortization	(60)	(168)
Duke Energy Ohio [Member] | Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	0	10
Accumulated amortization	0	(9)
Duke Energy Indiana [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	45	53
Accumulated amortization	(13)	(12)
Total intangible assets, net	32	41
Amortization expense	1	1	1
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2014	22
2015	1
2016	1
2017	1
2018	1
Pretax impairment charge		579	234
Duke Energy Indiana [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	21	29
Duke Energy Indiana [Member] | Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	24	24
Accumulated amortization	$ (13)	$ (12)