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Investments (Estimated Fair Value Of Investments) (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2022 | Dec. 31, 2021
Fixed maturity securities: |  |
Due in one year or less | $ 149,255 |
Due after one year through five years | 977,997 |
Due after five years through ten years | 633,232 |
Due after ten years | 2,327,827 |
Total | $ 4,088,311 | $ 4,031,523
External credit rating, non investment grade [Member] |  |
Credit Derivatives [Line Items] |  |
Percentage of fixed maturities | 0.60% |

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