Debt and Credit Facilities (Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Other Debt Matters [Abstract]
Subsidiary debt guaranteed by parent	$ 811,000,000	$ 734,000,000
Demand notes, maximum amount available for sale	3,000,000,000
Demand notes, maximum amount outstanding	1,500,000,000
Principal amount of demand notes	836,000,000	395,000,000
Other Loans [Abstract]
Other loans outstanding against cash surrender value of life insurance policies	571,000,000	496,000,000
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Carolinas [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Progress Energy [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Progress [Member]
Other Loans [Abstract]
Other loans outstanding against cash surrender value of life insurance policies	$ 48,000,000
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Florida [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Ohio [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Indiana [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65