Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (50)	$ 8	$ 121
State	1	11	31
Foreign	74	42	204
Total current	25	61	356
Deferred:
Federal	(136)	(355)	(1,036)
State	(33)	(63)	(283)
Foreign	(92)	(650)	(267)
Total deferred	(261)	(1,068)	(1,586)
Total income tax benefit	(236)	(1,007)	(1,230)
Total income tax provision - discontinued operations	0	31	129
Total income tax benefit - continuing operations	$ (236)	$ (1,038)	$ (1,359)