Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Income Statement [Abstract]
Revenues	$ 5,693	$ 5,660
Operating expenses:
Compensation and benefits	1,387	1,412
Fuel	770	854
Depreciation and amortization	675	661
Purchased services	538	503
Equipment rents	182	174
Materials and other	321	336
Total operating expenses	3,873	3,940
Operating income	1,820	1,720
Interest expense	272	265
Other (income) expense, net	(55)	(64)
Income before income taxes	1,603	1,519
Income Tax Expense (Benefit)	389	376
Net income	$ 1,214	$ 1,143