Income Taxes - Components of the Provision (Benefit) for Income Taxes (Detail) - USD ($) $ in Millions	3 Months Ended							12 Months Ended
	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. Federal:
Current								$ 2	$ (14)	$ 38
Deferred								(1)	(2)	3
U.S. Federal, Total								1	(16)	41
U.S. State:
Current									(1)	4
U.S. State, Total									(1)	4
Foreign
Current								3	5	18
Deferred									(4)	(1)
Foreign, Total								3	1	17
Income tax provision (benefit)	$ 23	$ (15)	$ (4)	$ 63	$ (67)	$ (10)	$ (2)	$ 4	$ (16)	$ 62