v2.4.0.8
Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details)
 9 Months Ended 12 Months Ended
Sep. 30, 2014
GWh
dth
Dec. 31, 2013
GWh
dth
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]    
Electricity-energy (Gigawatt-hours) 29,569 [1] 71,466 [1]
Natural gas (millions of decatherms) 659,000,000 636,000,000
Duke Energy Carolinas [Member]
    
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]    
Electricity-energy (Gigawatt-hours)    [1] 1,205 [1]
Natural gas (millions of decatherms)      
Progress Energy [Member]
    
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]    
Electricity-energy (Gigawatt-hours)    [1] 925 [1]
Natural gas (millions of decatherms) 319,000,000 363,000,000
Duke Energy Progress [Member]
    
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]    
Electricity-energy (Gigawatt-hours)    [1] 925 [1]
Natural gas (millions of decatherms) 117,000,000 141,000,000
Duke Energy Florida [Member]
    
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]    
Electricity-energy (Gigawatt-hours)    [1]    [1]
Natural gas (millions of decatherms) 202,000,000 222,000,000
Duke Energy Ohio [Member]
    
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]    
Electricity-energy (Gigawatt-hours) 25,680 [1] 69,362 [1]
Natural gas (millions of decatherms) 340,000,000 274,000,000
Duke Energy Indiana [Member]
    
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]    
Electricity-energy (Gigawatt-hours) 607 [1] 203 [1]
Natural gas (millions of decatherms)      
[1] Amounts at Duke Energy Ohio include intercompany positions that eliminate at Duke Energy.