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Components of Net Realized Investment Gains (Losses) (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Total net realized investment gains (losses) | $ (3,994) | $ (512) | $ (3,731) | $ 540
Equity securities, Gross realized gains | 38 | 295 | 322 | 1,384
Equity securities, Gross realized losses | (4,005) | (6) | (4,005) | (11)
Net realized gains (losses) | (3,967) | 289 | (3,683) | 1,373
Fixed Income Securities |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Gross realized gains | 8 | 5 | 69 | 54
Gross realized losses | (35) | (806) | (117) | (887)
Total net realized investment gains (losses) | $ (27) | $ (801) | $ (48) | $ (833)

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