Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Available for sale securities, amortized cost | $ 3,775,708 | $ 3,793,777 |
| Allowance for expected credit losses | 4,299 | 4,306 |
| Trading securities, cost | 13,487 | 14,202 |
| Equity investments at fair value, cost | 121,742 | 121,766 |
| Other investments, portion carried at fair value | 0 | 1,215 |
| Premium receivable, allowance for credit loss | $ 7,951 | $ 7,829 |
| Common shares, par value (in usd per share) | $ 0.01 | $ 0.01 |
| Common shares, shares authorized (in shares) | 100,000,000 | 100,000,000 |
| Common shares, shares issued (in shares) | 64,214,694 | 64,020,611 |
| Deferred tax expense (benefit) on accumulated other comprehensive income (loss) | $ (26,942) | $ (21,905) |
| Treasury shares (in shares) | 12,606,968 | 12,606,968 |
| X | ||||||||||
- Definition Other Investments, Fair Value Disclosure No definition available.
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- Definition Amount of tax expense (benefit) allocated to accumulated other comprehensive income (loss) attributable to parent. No definition available.
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- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). 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://www.xbrl.org/2009/role/commonPracticeRef
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- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The carrying value as of the balance sheet date of the estimated valuation allowance to reduce gross premiums receivable to net realizable value. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- References No definition available.
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| X | ||||||||||
- Definition Amortized cost of investments in debt securities classified as trading. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Number of previously issued common shares repurchased by the issuing entity and held in treasury. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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