Revenues - Accounts Receivable, Net (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivable, net	$ 1,399	$ 1,313
Freight Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, gross	1,043	1,067
Allowance for Credit Losses	(16)	(16)
Total Accounts Receivable, net	1,027	1,051
Non-Freight Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, gross	387	279
Allowance for Credit Losses	(15)	(17)
Total Accounts Receivable, net	$ 372	$ 262