Variable Interest Entities (Schedule of Accounts Receivable Securitizations) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	$ 2,222,000,000
Duke Energy Progress [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	650,000,000
Duke Energy Florida [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	225,000,000
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	400,000,000
Line of Credit Facility, Expiration Date	Oct. 01, 2016
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	300,000,000
Line of Credit Facility, Expiration Date	Dec. 01, 2016
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Debt Instrument, Face Amount	$ 225,000,000
Line of Credit Facility, Expiration Date	Mar. 01, 2017