Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Railway operating revenues	$ 12,180	$ 12,123	$ 12,156
Railway operating expenses
Compensation and benefits	2,922	2,823	2,819
Purchased services and rents	2,095	2,048	2,070
Fuel	932	987	1,170
Depreciation	1,393	1,353	1,298
Materials and other	634	333	832
Merger-related expenses	80	0	0
Restructuring and other charges	22	183	0
Eastern Ohio incident	(254)
Eastern Ohio incident		325	1,116
Total railway operating expenses	7,824	8,052	9,305
Income from railway operations	4,356	4,071	2,851
Other income – net	101	65	191
Interest expense on debt	792	807	722
Income before income taxes	3,665	3,329	2,320
Income taxes	792	707	493
Net income	$ 2,873	$ 2,622	$ 1,827
Earnings per share
Basic (in dollars per share)	$ 12.76	$ 11.58	$ 8.04
Diluted (in dollars per share)	$ 12.75	$ 11.57	$ 8.02