Organization and Basis of Presentation (Schedule of Excise Taxes) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 101	$ 168	$ 416	$ 457
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	4	46	93	124
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	63	89	214	230
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected		33	56	88
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	63	56	158	142
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	24	24	80	77
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 10	$ 9	$ 29	$ 26