Railway Operating Revenues - Schedule of Account Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Accounts receivable – net	$ 976	$ 848
Trade Accounts Receivable
Disaggregation of Revenue [Line Items]
Accounts receivable – net	741	629
Other Receivables
Disaggregation of Revenue [Line Items]
Accounts receivable – net	$ 235	$ 219

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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