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Investments - Estimated Fair Value Of Investments (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022
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Fixed maturity securities: |  |
Due in one year or less | $ 306,970 |
Due after one year through five years | 935,982 |
Due after five years through ten years | 888,429 |
Due after ten years | 2,187,955 |
Total | $ 4,319,336 | $ 4,088,311

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