Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 188	$ 159	$ 144
Amortization expense relating to capitalized computer software	$ 87	$ 61	$ 46