Schedule IV - Reinsurance Premiums Written and Premiums Earned (Details) - USD ($) $ in Millions |
12 Months Ended | ||||
|---|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
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| SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract] | |||||
| Insurance | $ 2,768.1 | $ 2,723.5 | $ 2,446.6 | ||
| Reinsurance | 1,905.1 | 1,885.8 | 1,521.0 | ||
| Ceded | (1,837.2) | (1,666.7) | (1,385.7) | ||
| Net written premiums | 2,836.0 | 2,942.6 | 2,581.9 | ||
| Gross Amount | 2,752.2 | 2,565.7 | 2,444.8 | ||
| Assumed From Other Companies | 1,850.0 | 1,822.1 | 1,562.0 | ||
| Ceded | (1,770.3) | (1,498.1) | (1,392.3) | ||
| Net premiums earned | [1] | $ 2,831.9 | $ 2,889.7 | $ 2,614.5 | |
| Percentage of Amount Assumed to Net Amount | 65.30% | 63.10% | 59.70% | ||
| Gross written premiums | $ 4,673.2 | $ 4,609.3 | $ 3,967.6 | ||
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- References No definition available.
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- Definition Amount of earned premiums assumed from other entities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of written premiums assumed from other entities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of earned premiums ceded to other entities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of written premiums ceded to other entities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount, before premiums ceded to other entities and premiums assumed by the entity, of premiums earned. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount, before premiums ceded to other entities and premiums assumed by the entity, of premiums written. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Percentage of assumed premium earned to premium earned after effects of reinsurance, as disclosed in supplementary reinsurance information. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of direct and assumed premiums written. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums written. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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