Investment in Affiliates and Related-Party Transactions - Schedule of Related Party in the Consolidated Income Statement Components (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Related Party Amounts Consolidated Income Statements [Abstract]
Total Expense	$ 9,571	$ 9,295	$ 9,158
Corporate Joint Venture \| Conrail
Related Party Amounts Consolidated Income Statements [Abstract]
Rents, Fees and Services	134	142	132
Purchase Price Amortization and Other	4	4	4
Equity Earnings	(57)	(69)	(54)
Total Expense	81	77	82
Related Party \| TTX
Related Party Amounts Consolidated Income Statements [Abstract]
Car Hire Rents	277	256	249
Equity Earnings	(43)	(50)	(49)
Total Expense	$ 234	$ 206	$ 200

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The amortization of the fair value write-up of fixed assets when the original purchase price from the acquisition was allocated based on fair value.

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Related Party Amounts Consolidated Income Statements [Abstract]

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Total amount of related party rents, fees and services in the Company's consolidated income statements.

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- Definition

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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- Definition

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Excludes Selling, General and Administrative Expense.

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