v3.5.0.2
Derivative Instruments (Details 2) (Details) - USD ($)
$ in Millions
Jun. 30, 2016
Dec. 31, 2015
Derivatives, Fair Value [Line Items]    
Derivative assets, current $ 1,231 $ 1,698
Long-term derivative assets 369 313
Total derivative assets 1,600 2,011
Derivative liabilities, current 1,360 1,734
Long-term derivative liabilities 512 473
Total derivative liabilities 1,872 2,207
Derivative, Fair Value, Net (272) (196)
Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 9 1
Total derivative liabilities 96 90
Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 1,591 2,010
Total derivative liabilities 1,776 2,117
Interest Rate Hedging Instruments    
Derivatives, Fair Value [Line Items]    
Derivative assets, current 0 0
Derivative Assets, Noncurrent 9 1
Total derivative assets 9 1
Current derivative liabilities 37 37
Derivative Liabilities, Noncurrent 59 53
Total derivative liabilities 96 90
Derivative, Fair Value, Net (87) (89)
Interest Rate Hedging Instruments | Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 9 1
Total derivative liabilities 96 90
Energy Related Derivative [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets, current 1,231 1,698
Derivative Assets, Noncurrent 360 312
Total derivative assets 1,591 2,010
Current derivative liabilities 1,323 1,697
Derivative Liabilities, Noncurrent 453 420
Total derivative liabilities 1,776 2,117
Derivative, Fair Value, Net (185) (107)
Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 1,591 2,010
Total derivative liabilities $ 1,776 $ 2,117