Restructuring Costs - Schedule of Accrued Restructuring Costs Activity (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Reserve [Roll Forward]
Beginning balance	$ 11
Restructuring costs, net	5	$ 2
Payments	(5)
Ending balance	11
Severance and termination costs
Restructuring Reserve [Roll Forward]
Beginning balance	7
Restructuring costs, net	4
Payments	(4)
Ending balance	7
Contract termination and other costs
Restructuring Reserve [Roll Forward]
Beginning balance	4
Restructuring costs, net	1
Payments	(1)
Ending balance	$ 4