Merger Agreement (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | |||
|---|---|---|---|---|
Jul. 28, 2025 |
Mar. 31, 2026 |
Mar. 31, 2025 |
Dec. 31, 2025 |
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| Business Combination [Line Items] | ||||
| Common stock, par or stated value per share (in dollars per share) | $ 1.00 | $ 1.00 | $ 1.00 | |
| Merger-related expenses | $ 52 | $ 0 | ||
| Union Pacific Merger | Union Pacific | ||||
| Business Combination [Line Items] | ||||
| Common stock, par or stated value per share (in dollars per share) | $ 2.50 | |||
| Business combination, consideration transferred, shares issued per acquiree share | 1 | |||
| Business combination, consideration transferred, shares issued per acquiree share (in dollars per share) | $ 88.82 | |||
| Specified termination fee | $ 2,500 | |||
| Union Pacific Merger | Norfolk Southern | ||||
| Business Combination [Line Items] | ||||
| Specified termination fee | $ 2,500 | |||
| X | ||||||||||
- Definition Business Combination, Consideration Transferred, Equity Interests Issued And Issuable, Cash Paid Per Acquiree Share No definition available.
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- Definition Business Combination, Consideration Transferred, Equity Interests Issued And Issuable, Entity Shares Issued Per Acquiree Share No definition available.
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- Definition Business Combination, Specified Termination Fee No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of expense for acquisition-related cost incurred to effect business combination. Includes, but is not limited to, finder's fee; advisory, legal, accounting, valuation, and other professional and consulting fees; and general administrative cost, including cost of maintaining internal acquisition department. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Face amount or stated value per share of common stock. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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