Derivatives and Hedging (Derivative Instruments That Contain Credit-Risk Related Contingent Features and Cash Collateral) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
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	$ 613	$ 525
Collateral aready posted	287	135
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	26	205
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Payables	39	30
Derivative, collateral, right to reclaim cash - not offset against net derivative	248	122
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	142	168
Collateral aready posted	8	10
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	135	158
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Payables	8	10
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	23	60
Collateral aready posted	0
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	23	60
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	119	108
Collateral aready posted	8	10
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	112	98
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Payables	8	10
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	611	355
Collateral aready posted	248	125
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	26	47
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Payables	31	19
Derivative, collateral, right to reclaim cash - not offset against net derivative	$ 217	$ 115