Derivatives and Risk Management Activities (Details 6) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Derivative Asset Positions
Gross Position - Asset	$ 246	$ 493
Netting Adjustment	(52)	(262)
Cash collateral received	(112)	(133)
Net Position - Asset	82us-gaap_DerivativeAssets	98us-gaap_DerivativeAssets
Derivative Liability Positions
Gross Position - Liability	(250)	(384)
Netting Adjustment	52	262
Net Position - Liability	(198)us-gaap_DerivativeLiabilities	(122)us-gaap_DerivativeLiabilities
Other current assets
Derivative Asset Positions
Net Position - Asset	64	71
Other long-term assets, net
Derivative Asset Positions
Net Position - Asset	18	27
Other current liabilities
Derivative Liability Positions
Net Position - Liability	(108)	(91)
Other long-term liabilities and deferred credits
Derivative Liability Positions
Net Position - Liability	$ (90)	$ (31)

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

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