Railway Operating Revenues - Schedule of Account Receivables (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable – net	$ 883	$ 920
Trade Accounts Receivable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable – net	664	682
Other Receivables
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable – net	219	238
Other Noncurrent Receivables
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net, noncurrent	$ 23	$ 23