Derivatives and Risk Management Activities (Details 6) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative Asset Positions
Gross Position - Asset	$ 493	$ 133
Netting Adjustment	(262)	(148)
Cash collateral received	(133)
Cash collateral paid		161
Net Position - Asset	98us-gaap_DerivativeAssets	146us-gaap_DerivativeAssets
Derivative Liability Positions
Gross Position - Liability	(384)	(157)
Netting Adjustment	262	148
Net Position - Liability	(122)us-gaap_DerivativeLiabilities	(9)us-gaap_DerivativeLiabilities
Other current assets
Derivative Asset Positions
Net Position - Asset	71	116
Other long-term assets
Derivative Asset Positions
Net Position - Asset	27	30
Other current liabilities
Derivative Liability Positions
Net Position - Liability	(91)	(8)
Other long-term liabilities
Derivative Liability Positions
Net Position - Liability	$ (31)	$ (1)

Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

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