Net Parent Investment - Components of Net Transfers (to) from Parent on the Condensed Combined Consolidated Statements of Cash Flows (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Related Party Transaction [Line Items]
Net transfers (to) from Parent	$ (9)	$ 35
Cash Pooling and General Financing Activities [Member]
Related Party Transaction [Line Items]
Net transfers (to) from Parent	$ (9)	(5)
Corporate Allocations [Member]
Related Party Transaction [Line Items]
Net transfers (to) from Parent		12
Income Taxes [Member]
Related Party Transaction [Line Items]
Net transfers (to) from Parent		$ 28