Risk Management, Derivative Instruments and Hedging Activities (Derivative Instruments That Contain Credit-Risk Related Contingent Features and Cash Collateral) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	$ 481	$ 466
Collateral aready posted	138	163
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	200	230
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Receivables	40	73
Derivative, collateral, right to reclaim cash - not offset against net derivative	101	93
Progress Energy [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	211	286
Collateral aready posted	26	59
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	185	227
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Receivables	26	58
Derivative, collateral, right to reclaim cash - not offset against net derivative		1
Duke Energy Progress [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	82	108
Collateral aready posted	5	9
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	77	99
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Receivables	5	9
Duke Energy Florida [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	129	178
Collateral aready posted	21	50
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	108	128
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Receivables	21	49
Derivative, collateral, right to reclaim cash - not offset against net derivative		1
Duke Energy Ohio [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	268	176
Collateral aready posted	106	104
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	15	2
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Receivables	13	15
Derivative, collateral, right to reclaim cash - not offset against net derivative	92	92
Duke Energy Indiana [Member]
Information Regarding Cash Collateral Under Master Netting Arrangements
Derivative, collateral, right to reclaim cash - not offset against net derivative	$ 3