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Investments - Maturities of Fixed Maturities (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2022 | Dec. 31, 2021
Amortized Cost, net |  |
Due in 1 year or less | $ 235.4 |
Due after 1 year through 5 years | 1,423.3 |
Due after 5 years through 10 years | 1,558.5 |
Due after 10 years through 20 years | 1,477.9 |
Due after 20 years | 1,061.8 |
Amortized Cost, net | 5,756.9 | $ 5,797.7
Fair Value |  |
Due in 1 year or less | 226.7 |
Due after 1 year through 5 years | 1,362.4 |
Due after 5 years through 10 years | 1,448.0 |
Due after 10 years through 20 years | 1,296.2 |
Due after 20 years | 851.7 |
Total | $ 5,185.0 | $ 6,239.3
Percent of Total Fair Value |  |
Due in 1 year or less | 4.40% |
Due after 1 year through 5 years | 26.30% |
Due after 5 years through 10 years | 27.90% |
Due after 10 years through 20 years | 25.00% |
Due after 20 years | 16.40% |
Total | 100.00% |
Average option-adjusted duration, in years | 6 years 4 months 24 days |

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