Derivative and Other Financial Instruments (Schedule of Offsetting Derivative Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative assets
Gross amounts recognized in the Balance Sheet	$ 63	$ 45
Gross amounts not offset in the Balance Sheet	17	6
Net amount	46	39
Derivative liabilities
Gross amounts recognized in the Balance Sheet	23	37
Gross amounts not offset in the Balance Sheet	17	6
Net amount	$ 6	$ 31

Fair value, after effects of master netting arrangements, deduction of assets not subject to a master netting arrangement and elected not to be offset, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, offset against an obligation to return collateral.

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+ References

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