Organization and Basis of Presentation (Schedule of Excise Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 87	$ 97	$ 178	$ 197
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	7	9	15	18
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	50	57	96	106
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	4	4	9	8
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	46	53	87	98
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	22	23	51	55
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 8	$ 8	$ 16	$ 18