Revenues - Revenues Disaggregated by Lines of Business (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 3,413	$ 2,813
Total Merchandise
Disaggregation of Revenue [Line Items]
Revenue	1,921	1,818
Chemicals
Disaggregation of Revenue [Line Items]
Revenue	618	580
Agricultural and Food Products
Disaggregation of Revenue [Line Items]
Revenue	387	349
Forest Products
Disaggregation of Revenue [Line Items]
Revenue	228	220
Automotive
Disaggregation of Revenue [Line Items]
Revenue	227	236
Metals and Equipment
Disaggregation of Revenue [Line Items]
Revenue	197	186
Minerals
Disaggregation of Revenue [Line Items]
Revenue	144	125
Fertilizers
Disaggregation of Revenue [Line Items]
Revenue	120	122
Intermodal
Disaggregation of Revenue [Line Items]
Revenue	527	468
Coal
Disaggregation of Revenue [Line Items]
Revenue	533	384
Trucking
Disaggregation of Revenue [Line Items]
Revenue	230	0
Other
Disaggregation of Revenue [Line Items]
Revenue	$ 202	$ 143