Leases - Schedule Of Lease-Related Assets And Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets:
Operating leases	$ 2,024	$ 1,834
Finance leases	553	520
Total lease assets	2,577	2,354
Liabilities
Operating leases	379	350
Finance leases	128	87
Operating leases	1,673	1,499
Finance leases	494	470
Total lease liabilities	$ 2,674	$ 2,406
Weighted-average remaining term:
Operating leases	10 years 4 months 24 days	10 years 9 months 18 days
Finance leases	11 years 6 months	12 years
Weighted-average discount rate:
Operating leases	4.80%	5.30%
Finance leases	5.40%	6.00%