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Receivables - Narrative (Details) - National Oil Companies of Mauritania And Senegal - Carry Advance Agreements - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2026 | Jun. 30, 2025 | Jun. 30, 2026 | Jun. 30, 2025 | Dec. 31, 2025
Oil and Gas Joint Interest Billing Receivables [Line Items] |  |  |  |  |
Long-term receivables | $ 450.9 |  | $ 450.9 |  | $ 437.1
Interest income, long-term notes receivable | $ 7.0 | $ 6.2 | $ 13.8 | $ 11.5 |

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- Definition Interest Income, Long-Term Notes Receivable + References No definition available. + Details
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- References No definition available. + Details
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Namespace Prefix: | kos_
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- Details
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- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |