Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 204	$ 256	$ 400
State	94	132	56
Foreign	36	40	37
Current tax total	334	428	493
Deferred:
Federal	94	59	(316)
State	8	(32)	62
Foreign	(2)	(2)	3
Deferred tax total	100	25	(251)
Income tax expense	$ 434	$ 453	$ 242