Leases - Schedule Of Supplemental Cash Flow Related To Leases (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 133	$ 153
Operating cash flows from finance leases	0	1
Financing cash flows from finance leases	3	3
Right of use assets obtained in exchange for lease liabilities:
Operating leases	53	124
Finance leases	$ 0	$ 7