Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Effective Tax Rate
Income before income taxes	$ 313	$ 186	$ 620	$ 119
Income tax expense from continuing operations	$ 7	$ 1	$ 19	$ 3
Effective tax rate	2.20%	0.50%	3.10%	2.50%
Uncertain Tax Benefits
Non-current tax liability for uncertain tax benefits	$ 47		$ 47
Accrued interest related to unrecognized tax benefits	2		2
Uncertain tax benefits, penalties and interest accrued	$ 5		$ 5

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount recognized for uncertainty in income taxes classified as noncurrent.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of interest expense accrued for an underpayment of income taxes.

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