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Investments - Maturities of Fixed Maturities (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Amortized Cost, net |  |  |
Due in 1 year or less | $ 298.6 |  |
Due after 1 year through 5 years | 1,482.4 |  |
Due after 5 years through 10 years | 1,435.1 |  |
Due after 10 years through 20 years | 1,426.3 |  |
Due after 20 years | 1,010.5 |  |
Amortized Cost, net | 5,652.9 | $ 5,756.9 |
Fair Value |  |  |
Due in 1 year or less | 294.1 |  |
Due after 1 year through 5 years | 1,435.5 |  |
Due after 5 years through 10 years | 1,371.5 |  |
Due after 10 years through 20 years | 1,282.6 |  |
Due after 20 years | 851.6 |  |
Total | $ 5,235.3 | $ 5,185.0 | [1]
Percent of Total Fair Value |  |  |
Due in 1 year or less | 5.60% |  |
Due after 1 year through 5 years | 27.40% |  |
Due after 5 years through 10 years | 26.20% |  |
Due after 10 years through 20 years | 24.50% |  |
Due after 20 years | 16.30% |  |
Total | 100.00% |  |
[1] | Recast for the adoption of ASU 2018-12. See Note 1 of the Consolidated Financial Statements

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