Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Revenues	$ 6,693	$ 5,790	$ 19,301	$ 17,000
Operating expenses:
Compensation and benefits	1,496	1,183	3,968	3,529
Fuel	1,272	705	3,409	1,948
Purchased services	670	688	2,008	2,039
Depreciation and amortization	636	611	1,883	1,842
Equipment rents	180	170	544	507
Materials and other	331	171	961	766
Total operating expenses	4,585	3,528	12,773	10,631
Operating income	2,108	2,262	6,528	6,369
Interest expense	258	256	767	775
Other (income) expense, net	(34)	(23)	(83)	(73)
Income before income taxes	1,884	2,029	5,844	5,667
Income Tax Expense (Benefit)	442	491	1,367	1,362
Net income	$ 1,442	$ 1,538	$ 4,477	$ 4,305