Organization and Basis of Presentation (Schedule of Excise Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 107	$ 109	$ 285	$ 308
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	6	9	21	27
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	65	67	161	174
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	4	4	13	12
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	61	63	148	162
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	26	24	77	80
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 10	$ 9	$ 26	$ 27