Provision (Benefit) for Income Taxes from Continuing Operations (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Current Federal	$ (57)	$ 14	$ 79
Current State	1	6	30
Current Foreign	1	3	37
Current Income Tax Expense (Benefit), Total	(55)	23	146
Deferred Federal	(96)	3	2
Deferred State	(63)	1	1
Deferred Foreign	(6)	3	1
Deferred income taxes	(165)	7	4
Income tax provision (benefit) – continuing operations	$ (220)	$ 30	$ 150