Leasing - Schedule of Lease Expense and Operating Cash Flows (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Costs from operating leases	$ 16	$ 19	$ 54	$ 57
Variable lease payments	4	2	9	7
Short-term rental expense	$ 1	$ 1	$ 2	$ 2