Provision for (Benefit from) Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal	$ 0	$ (1)	$ (32)
State	5	3	3
Foreign	37	63	40
Current income tax provision (benefit)	42	65	11
Deferred
Federal	(205)	51	45
State	(5)	5	(1)
Foreign	18	(5)	14
Deferred income tax provision	(192)	51	58
Provision for (benefit from) income taxes	$ (150)	$ 116	$ 69