Income Taxes - Deferred Tax Assets and Liabilities, Net (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Deferred income taxes	$ 21	$ 21
Deferred income taxes (long-term liability)	(421)	(429)
Net Deferred Tax Assets (Liabilities)	$ (400)	$ (408)

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards classified as noncurrent.

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Balance Type:	debit
Period Type:	instant