v2.4.0.8
Derivative and Hedging Activities - Derivative Instruments Table (Details) (USD $)
In Millions, unless otherwise specified
Jun. 30, 2014
Dec. 31, 2013
Derivative [Line Items]    
Fair Value $ (755) $ (551)
Natural Gas [Member]
   
Derivative [Line Items]    
Volume, Energy Measurement 949,000,000,000,000 1,009,000,000,000,000
Fair Value (278) (237)
Natural Gas [Member] | Swap [Member]
   
Derivative [Line Items]    
Volume, Energy Measurement 293,000,000,000,000 448,000,000,000,000
Fair Value (75) (23)
Natural Gas [Member] | Three Way Collar [Member]
   
Derivative [Line Items]    
Volume, Energy Measurement 335,000,000,000,000 288,000,000,000,000
Fair Value (27) (7)
Natural Gas [Member] | Collar [Member]
   
Derivative [Line Items]    
Volume, Energy Measurement 22,000,000,000,000 0
Fair Value 4 0
Natural Gas [Member] | Call Option [Member]
   
Derivative [Line Items]    
Volume, Energy Measurement 193,000,000,000,000 193,000,000,000,000
Fair Value (195) (210)
Natural Gas [Member] | Swaption [Member]
   
Derivative [Line Items]    
Volume, Energy Measurement 0 12,000,000,000,000
Fair Value 0 0
Natural Gas [Member] | Basis Swap [Member]
   
Derivative [Line Items]    
Volume, Energy Measurement 106,000,000,000,000 68,000,000,000,000
Fair Value 15 3
Crude Oil [Member]
   
Derivative [Line Items]    
Volume, Volume Measurement 61,800,000 68,200,000
Fair Value (477) (314)
Crude Oil [Member] | Swap [Member]
   
Derivative [Line Items]    
Volume, Volume Measurement 18,300,000 25,300,000
Fair Value (146) (50)
Crude Oil [Member] | Three Way Collar [Member]
   
Derivative [Line Items]    
Volume, Volume Measurement 4,400,000 0
Fair Value (12) 0
Crude Oil [Member] | Call Option [Member]
   
Derivative [Line Items]    
Volume, Volume Measurement 38,900,000 42,500,000
Fair Value (320) (265)
Crude Oil [Member] | Basis Swap [Member]
   
Derivative [Line Items]    
Volume, Volume Measurement 200,000 400,000
Fair Value $ 1 $ 1