Income Taxes - Components of (Benefit) Provision for Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
U.S. Federal	$ 16	$ 34	$ 21
State	3	6	2
Foreign	11	3	9
Total current	30	43	32
Deferred:
U.S. Federal	3	(18)	(2,373)
Foreign	2	(2)	(5)
Total deferred	5	(20)	(2,378)
Total provision (benefit) for income taxes	$ 35	$ 23	$ (2,346)