Variable Interest Entities (Schedule of Accounts Receivable Securitizations)(Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Debt Instrument, Face Amount	$ 2,700,000,000	$ 2,922,000,000
Duke Energy Carolinas [Member]
Variable Interest Entity [Line Items]
Debt Instrument, Face Amount	500,000,000
Duke Energy Progress [Member]
Variable Interest Entity [Line Items]
Debt Instrument, Face Amount	1,200,000,000	1,350,000,000
Duke Energy Florida [Member]
Variable Interest Entity [Line Items]
Debt Instrument, Face Amount		$ 225,000,000
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Debt Instrument, Face Amount	$ 425,000,000
Line of credit facility, expiration date	Dec. 01, 2018
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Debt Instrument, Face Amount	$ 300,000,000
Line of credit facility, expiration date	Feb. 01, 2019
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Debt Instrument, Face Amount	$ 225,000,000
Line of credit facility, expiration date	Mar. 01, 2017