Risk Management, Derivative Instruments And Hedging Activities (Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Aggregate Fair Value Amounts of Derivative Instruments in a Net Liability Position	$ 466	$ 96
Collateral Already Posted	163	36
Additional Cash Collateral or Letters of Credit in the Event Credit-risk-related Contingent Features were Triggered at the End of the Reporting Period	230	5
Progress Energy [Member]
Derivative [Line Items]
Aggregate Fair Value Amounts of Derivative Instruments in a Net Liability Position	286	489
Collateral Already Posted	59	147
Additional Cash Collateral or Letters of Credit in the Event Credit-risk-related Contingent Features were Triggered at the End of the Reporting Period	227	342
Progress Energy Carolinas [Member]
Derivative [Line Items]
Aggregate Fair Value Amounts of Derivative Instruments in a Net Liability Position	108	152
Collateral Already Posted	9	24
Additional Cash Collateral or Letters of Credit in the Event Credit-risk-related Contingent Features were Triggered at the End of the Reporting Period	99	128
Progress Energy Florida [Member]
Derivative [Line Items]
Aggregate Fair Value Amounts of Derivative Instruments in a Net Liability Position	178	337
Collateral Already Posted	50	123
Additional Cash Collateral or Letters of Credit in the Event Credit-risk-related Contingent Features were Triggered at the End of the Reporting Period	128	214
Duke Energy Ohio [Member]
Derivative [Line Items]
Aggregate Fair Value Amounts of Derivative Instruments in a Net Liability Position	176	94
Collateral Already Posted	104	35
Additional Cash Collateral or Letters of Credit in the Event Credit-risk-related Contingent Features were Triggered at the End of the Reporting Period	$ 2	$ 5