v3.2.0.727
Derivative Instruments (Details 2) (Details) - USD ($)
$ in Millions
Jun. 30, 2015
Dec. 31, 2014
Derivatives, Fair Value [Line Items]    
Derivative assets, current $ 1,607 $ 2,058
Long-term derivative assets 637 439
Total derivative assets 2,244 2,497
Derivative liabilities, current 1,407 1,782
Long-term derivative liabilities 453 444
Total derivative liabilities 1,860 2,226
Derivative, Fair Value, Net 384 271
Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 3 4
Total derivative liabilities 105 112
Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 2,241 2,493
Total derivative liabilities 1,755 2,114
Interest Rate Swap [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets, current 0 0
Derivative Assets, Noncurrent 3 4
Total derivative assets 3 4
Current derivative liabilities 42 44
Derivative Liabilities, Noncurrent 63 70
Total derivative liabilities 105 114
Derivative, Fair Value, Net (102) (110)
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 3 4
Total derivative liabilities 105 112
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 0 0
Total derivative liabilities 0 2
Energy Related Derivative [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets, current 1,607 2,058
Derivative Assets, Noncurrent 634 435
Total derivative assets 2,241 2,493
Current derivative liabilities 1,365 1,738
Derivative Liabilities, Noncurrent 390 374
Total derivative liabilities 1,755 2,112
Derivative, Fair Value, Net 486 381
Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Total derivative assets 2,241 2,493
Total derivative liabilities $ 1,755 $ 2,112