Revenue from Contracts with Customers Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 6,021	$ 6,147	$ 17,676	$ 17,649
Freight Revenue	5,723	5,812	16,763	16,684
Total other revenues	298	335	913	965
Consumer Products
Disaggregation of Revenue [Line Items]
Revenues	1,973	2,002	5,878	5,841
Industrial Products
Disaggregation of Revenue [Line Items]
Revenues	1,588	1,576	4,637	4,416
Agricultural Products
Disaggregation of Revenue [Line Items]
Revenues	1,166	1,165	3,500	3,499
Coal
Disaggregation of Revenue [Line Items]
Revenues	996	1,069	2,748	2,928
Non-rail logistics subsidiary
Disaggregation of Revenue [Line Items]
Revenues	199	235	595	641
Accessorial and other
Disaggregation of Revenue [Line Items]
Revenues	$ 99	$ 100	$ 318	$ 324