Revenues - Revenues Disaggregated by Lines of Business (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 3,895	$ 3,292	$ 11,123	$ 9,095
Total Merchandise
Disaggregation of Revenue [Line Items]
Revenue	2,143	1,881	6,165	5,602
Chemicals
Disaggregation of Revenue [Line Items]
Revenue	678	624	1,962	1,810
Agricultural and Food Products
Disaggregation of Revenue [Line Items]
Revenue	428	343	1,227	1,062
Automotive
Disaggregation of Revenue [Line Items]
Revenue	274	209	769	661
Forest Products
Disaggregation of Revenue [Line Items]
Revenue	264	231	743	684
Metals and Equipment
Disaggregation of Revenue [Line Items]
Revenue	211	206	624	596
Minerals
Disaggregation of Revenue [Line Items]
Revenue	180	162	494	439
Fertilizers
Disaggregation of Revenue [Line Items]
Revenue	108	106	346	350
Intermodal
Disaggregation of Revenue [Line Items]
Revenue	604	509	1,733	1,488
Coal
Disaggregation of Revenue [Line Items]
Revenue	624	460	1,808	1,267
Trucking
Disaggregation of Revenue [Line Items]
Revenue	251	200	740	200
Other
Disaggregation of Revenue [Line Items]
Revenue	$ 273	$ 242	$ 677	$ 538