Derivatives and Risk Management Activities (Details 6) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Derivative Asset Positions
Gross Position - Asset	$ 184	$ 493
Netting Adjustment	(63)	(262)
Cash collateral received	(46)	(133)
Net Position - Asset	75	98
Derivative Liability Positions
Gross Position - Liability	(92)	(384)
Netting Adjustment	63	262
Net Position - Liability	(29)	(122)
Other current assets
Derivative Asset Positions
Net Position - Asset	46	71
Other long-term assets, net
Derivative Asset Positions
Net Position - Asset	29	27
Other current liabilities
Derivative Liability Positions
Net Position - Liability	(25)	(91)
Other long-term liabilities and deferred credits
Derivative Liability Positions
Net Position - Liability	$ (4)	$ (31)