Organization and Basis of Presentation (Schedule of Unbilled Revenues with Restricted Receivables) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	$ 798	$ 937
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	285	323
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	232	189
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	131	120
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	101	69
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables		55
Duke Energy Ohio [Member] | Cinergy Receivables [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	54	89
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	26	5
Duke Energy Indiana [Member] | Cinergy Receivables [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	$ 94	$ 144