v2.4.0.8
Regulatory Matters (Schedule of Net Carrying Value Of Facilities As Well As the Remaining Non-current Regulatory Assets) (Details) (USD $)
In Millions, unless otherwise specified
 9 Months Ended
Sep. 30, 2014
MW
Dec. 31, 2013
Public Utilities, General Disclosures [Line Items]    
Capacity (in MW) 2,297  
Remaining net book value (in millions) $ 69,595 $ 69,490
Generation Facilities To Be Retired [Member]
    
Public Utilities, General Disclosures [Line Items]    
Remaining net book value (in millions) 256 [1]  
Duke Energy Carolinas [Member]
    
Public Utilities, General Disclosures [Line Items]    
Capacity (in MW) 200 [2]  
Remaining net book value (in millions) 25,126 23,012
Duke Energy Carolinas [Member] | Generation Facilities To Be Retired [Member]
    
Public Utilities, General Disclosures [Line Items]    
Remaining net book value (in millions) 19 [1],[2]  
Progress Energy [Member]
    
Public Utilities, General Disclosures [Line Items]    
Capacity (in MW) 873  
Remaining net book value (in millions) 24,399 23,382
Progress Energy [Member] | Generation Facilities To Be Retired [Member]
    
Public Utilities, General Disclosures [Line Items]    
Remaining net book value (in millions) 109 [1]  
Duke Energy Florida [Member]
    
Public Utilities, General Disclosures [Line Items]    
Capacity (in MW) 873 [3]  
Remaining net book value (in millions) 9,815 9,611
Duke Energy Florida [Member] | Generation Facilities To Be Retired [Member]
    
Public Utilities, General Disclosures [Line Items]    
Remaining net book value (in millions) 109 [1],[3]  
Duke Energy Ohio [Member]
    
Public Utilities, General Disclosures [Line Items]    
Capacity (in MW) 556 [4]  
Remaining net book value (in millions) 4,905 8,235
Duke Energy Ohio [Member] | Generation Facilities To Be Retired [Member]
    
Public Utilities, General Disclosures [Line Items]    
Remaining net book value (in millions) 9 [1],[4]  
Duke Energy Indiana [Member]
    
Public Utilities, General Disclosures [Line Items]    
Capacity (in MW) 668 [5]  
Remaining net book value (in millions) 8,780 8,576
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member]
    
Public Utilities, General Disclosures [Line Items]    
Remaining net book value (in millions) $ 119 [1],[5]  
[1] Included in Property, plant and equipment, net as of September 30, 2014, on the Condensed Consolidated Balance Sheets.
[2] Includes Lee Units 1 and 2. Excludes 170 MW Lee Unit 3 that is expected to be converted to gas in 2014. Duke Energy Carolinas expects to retire or convert these units by December 2020 in conjunction with a settlement agreement associated with the Cliffside Unit 6 air permit.
[3] Includes Crystal River Units 1 and 2.
[4] Includes Beckjord Units 5 and 6 and Miami Fort Unit 6. Beckjord units have no remaining book value and were retired October 1, 2014.
[5] Includes Wabash River Units 2 through 6. Wabash River Unit 6 is being evaluated for potential conversion to gas. Duke Energy Indiana committed to retire or convert these units by June 2018 in conjunction with a settlement agreement associated with the Edwardsport air permit.