Organization and Basis of Presentation (Schedule of Unbilled Revenues with Restricted Receivables) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	$ 884	$ 937
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	326	323
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	269	189
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	157	120
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	112	69
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	0	55
Duke Energy Ohio [Member] | Cinergy Receivables [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	64	89
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	27	5
Duke Energy Indiana [Member] | Cinergy Receivables [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	$ 102	$ 144