Investment in Affiliates and Related-Party Transactions - Schedule of Equity-method Investments in Affiliates (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Related Party Transaction [Line Items]
Total	$ 2,520	$ 2,397	[1]
Corporate Joint Venture | Conrail
Related Party Transaction [Line Items]
Total	1,245	1,175
Affiliated Entity
Related Party Transaction [Line Items]
Total	2,520	2,397
Affiliated Entity | TTX
Related Party Transaction [Line Items]
Total	1,012	961
Affiliated Entity | Oher Equity Method and Cost Method Investments
Related Party Transaction [Line Items]
Total	$ 263	$ 261

[1] See Note 20, Revision of Prior Period Financial Statements.