Leases - Schedule Of Lease-Related Assets And Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets:
Operating leases	$ 2,113	$ 2,024
Finance leases	637	553
Total lease assets	$ 2,750	$ 2,577
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Operating leases	Operating leases
Liabilities
Operating leases	$ 392	$ 379
Finance leases	143	128
Right-of-use operating lease obligations	1,755	1,673
Finance leases	577	494
Total lease liabilities	$ 2,867	$ 2,674
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Less amounts due within one year	Less amounts due within one year
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long-term Debt, Excluding Current Maturities	Long-term Debt, Excluding Current Maturities
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Accrued Liabilities, Current	Other Accrued Liabilities, Current
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Right-of-use operating lease obligations	Right-of-use operating lease obligations
Weighted-average remaining term:
Operating leases	10 years 2 months 12 days	10 years 4 months 24 days
Finance leases	10 years 4 months 24 days	11 years 6 months
Weighted-average discount rate:
Operating leases	4.40%	4.80%
Finance leases	4.40%	5.40%