Schedule of Intangible Assets Amortization Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 62	$ 65	$ 59
Licensing Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	33	35	31
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	24	23	21
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 5	$ 7	$ 7