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Legal Proceedings and Other Contingencies Legal Proceedings and Other Contingencies (Details) - Almasy, et al. v. Norfolk Southern Corp | 3 Months Ended | 6 Months Ended
--- | --- | ---
Mar. 31, 2024 USD ($) | Jun. 30, 2024 USD ($) individual_resident
Other Commitments [Line Items] |  |
Number of individual residents | individual_resident |  | 40
Litigation Settlement, Amount Awarded to Other Party | $ 600,000,000 |
Number of objections |  | $ 40

X
- Definition Number of individual residents + References No definition available. + Details
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Balance Type: | na
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- Definition Number of objections + References No definition available. + Details
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Namespace Prefix: | gmt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Amount awarded to other party in judgment or settlement of litigation. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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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. + References No definition available. + Details
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- Details
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Namespace Prefix: |
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