Business Combinations - Narrative (Details) $ in Millions			3 Months Ended	12 Months Ended		22 Months Ended
	Jun. 01, 2022 USD ($) mi	Jul. 01, 2021 USD ($) terminalAndFacility	Dec. 31, 2020 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2023 mi
Business Acquisition [Line Items]
Number of rail route miles | mi							20,000
Pan Am Systems, Inc.
Business Acquisition [Line Items]
Business combination, consideration transferred	$ 600
Business combination, consideration transferred, equity interests issued and issuable	422
Cash paid for acquisition	178
Deposit paid to acquire business classified as other investing activities			$ 30
Properties acquired	$ 600
Acquisition related costs				$ 22	$ 10	$ 32
Pan Am Systems, Inc. | Pan Am Systems, Inc.
Business Acquisition [Line Items]
Number of rail route miles | mi	1,200
Number of partial interests in rail route miles (more than) | mi	600
Quality Carriers, Inc.
Business Acquisition [Line Items]
Cash paid for acquisition		$ 544
Cash and cash equivalents acquired		3
Properties acquired		225
Acquisition related costs		$ 17
Quality Carriers, Inc. | Quality Carriers, Inc. | United States, Canada and Mexico
Business Acquisition [Line Items]
Number of terminals and facilities (over) | terminalAndFacility		100