Organization and Basis of Presentation (Schedule of Excise Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 97	$ 151	$ 197	$ 318
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	9	43	18	89
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	57	74	106	151
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	4	24	8	56
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	53	50	98	95
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	23	25	55	59
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 8	$ 9	$ 18	$ 19