Investments - Additional Information (Detail) - USD ($) |
3 Months Ended | 9 Months Ended | 12 Months Ended | |
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2026 |
Sep. 30, 2025 |
Dec. 31, 2025 |
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| Investments, Debt and Equity Securities [Abstract] | ||||
| Principal amount of bonds and certificates of deposit | $ 945,000,000 | $ 945,000,000 | ||
| Securities exceeding 10% of Shareholders' Equity | 0 | 0 | $ 0 | $ 0 |
| Non-income producing securities | 0 | 0 | ||
| Debt securities, available-for-sale, allowance for credit loss, not previously recorded | 0 | 0 | ||
| Debt securities, available-for-sale, allowance for credit loss | $ 0 | 0 | 0 | 0 |
| Debt securities, available-for-sale, allowance for credit loss, write-off | $ 0 | $ 0 | $ 0 | |
| investment income, percent change year-over-year | 12.00% | |||
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- Definition investment income, percent change, period over prior year period No definition available.
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- Definition Fair value of fixed-maturity securities that were non-income producing during the preceding 12 months. No definition available.
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- Definition Securities held in the portfolio with a single issuer for which the aggregate cost or fair value exceeds 10% of shareholders' equity. Excludes U.S. Government Obligations. No definition available.
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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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- Definition Amount of expense 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), for which no credit loss was previously recorded. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of writeoff 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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- Definition The carrying amount of the asset transferred to a third party to serve as a deposit, which typically serves as security against failure by the transferor to perform under terms of an agreement. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- References No definition available.
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