Accumulated Other Comprehensive Loss Changes in Composition of Accumulated Other Comprehensive Income or Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance as of beginning of period	$ (511)	$ (185)	$ (239)
Foreign currency translation adjustments	(210)	(325)	63
Net unrealized gains (losses) on available-for-sale securities	(2)	(1)	(9)
Total other comprehensive income (loss)	(212)	(326)	54
Balance as of end of period	(723)	(511)	(185)
Foreign currency translation adjustments
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance as of beginning of period	(512)	(187)	(250)
Foreign currency translation adjustments	(210)	(325)	63
Balance as of end of period	(722)	(512)	(187)
Unrealized gains on available-for-sale securities
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance as of beginning of period	1	2	11
Net unrealized gains (losses) on available-for-sale securities	(2)	(1)	(9)
Balance as of end of period	$ (1)	$ 1	$ 2