Revenues - Accounts Receivable, Net (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivable, net	$ 1,489	$ 1,148
Freight Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, gross	1,142	951
Allowance for Credit Losses	(14)	(14)
Total Accounts Receivable, net	1,128	937
Non-Freight Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, gross	375	225
Allowance for Credit Losses	(14)	(14)
Total Accounts Receivable, net	$ 361	$ 211