Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Statement [Abstract]
Revenues	$ 6,010	$ 5,904	$ 17,445	$ 17,303
Operating expenses:
Compensation and benefits	1,400	1,407	4,159	4,140
Fuel	772	799	2,240	2,475
Depreciation and amortization	687	648	2,045	1,975
Purchased services	552	517	1,606	1,528
Equipment rents	180	185	533	532
Materials and other	271	293	881	1,055
Total operating expenses	3,862	3,849	11,464	11,705
Operating income	2,148	2,055	5,981	5,598
Interest expense	279	275	821	807
Other (income) expense, net	(43)	(66)	(164)	(196)
Income before income taxes	1,912	1,846	5,324	4,987
Income Tax Expense (Benefit)	463	463	1,195	1,234
Net income	$ 1,449	$ 1,383	$ 4,129	$ 3,753