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Municipal Bond Guarantee Reinsurance - Schedule of Municipal Bond Guarantee Insured Obligations (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2025 USD ($) contract | Dec. 31, 2024 USD ($) contract
Subsidiary - HG Global | Maximum |  |
Guarantor Obligations [Line Items] |  |
Percentage of par value of policy reinsured | 15.00% |
HG Global |  |
Guarantor Obligations [Line Items] |  |
Contracts outstanding | contract | 17,377 | 15,884
Remaining weighted average contract period(in years) | 11 years 7 months 6 days | 11 years 2 months 12 days
Outstanding par value of policies assumed (in millions) | $ 20,559.9 | $ 18,503.3
Gross unearned insurance premiums (in millions) | $ 327.9 | $ 297.3

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