Income Taxes (Income before Income Taxes) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income (loss) before income taxes	$ (296)	$ (661)	$ (339)
Domestic [Member]
Income (loss) before income taxes	(287)	(638)	(362)
Foreign [Member]
Income (loss) before income taxes	$ (9)	$ (23)	$ 23

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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