Leases - Schedule of undiscounted cash flows to the finance lease liabilities and operating lease liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Operating Lease Liabilities, Payments Due [Abstract]
Year 1	$ 438	$ 431
Year 2	378	366
Year 3	320	307
Year 4	267	255
Year 5	219	207
Thereafter	1,148	1,136
Total minimum lease payments	2,770	2,702
Less: amount of lease payments representing interest	(623)	(650)
Present value of future minimum lease payments	2,147	2,052
Less: current obligations under leases	(392)	(379)
Long-term lease obligations	1,755	1,673
Finance Lease Liabilities, Payments, Due [Abstract]
Year 1	165	155
Year 2	126	125
Year 3	132	81
Year 4	98	82
Year 5	70	51
Thereafter	350	353
Total minimum lease payments	941	847
Less: amount of lease payments representing interest	(221)	(225)
Present value of future minimum lease payments	720	622
Less: current obligations under leases	(143)	(128)
Long-term lease obligations	$ 577	$ 494