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SCHEDULE I - SUMMARY OF INVESTMENTS-OTHER THAN INVESTMENTS IN RELATED PARTIES (Details) $ in Millions | Dec. 31, 2023 USD ($)
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Summary of investments other than investments in related parties |
Cost | $ 5,883.8
Carrying Value | 6,388.7
Fair Value | 6,388.7
Fixed maturity investments |
Summary of investments other than investments in related parties |
Cost | 2,198.4
Carrying Value | 2,109.3
Fair Value | 2,109.3
U.S. Government and agency obligations |
Summary of investments other than investments in related parties |
Cost | 209.0
Carrying Value | 204.9
Fair Value | 204.9
Debt securities issued by corporations |
Summary of investments other than investments in related parties |
Cost | 1,085.9
Carrying Value | 1,045.0
Fair Value | 1,045.0
Municipal obligations |
Summary of investments other than investments in related parties |
Cost | 275.1
Carrying Value | 260.9
Fair Value | 260.9
Mortgage and asset-backed securities |
Summary of investments other than investments in related parties |
Cost | 417.2
Carrying Value | 389.4
Fair Value | 389.4
Collateralized loan obligations |
Summary of investments other than investments in related parties |
Cost | 211.2
Carrying Value | 209.1
Fair Value | 209.1
Short-term investments |
Summary of investments other than investments in related parties |
Cost | 1,487.0
Carrying Value | 1,487.9
Fair Value | 1,487.9
Equity Method Investments | Investment in MediaAlpha |
Summary of investments other than investments in related parties |
Cost | 59.2
Carrying Value | 254.9
Fair Value | 254.9
Common equity securities - Industrial, Miscellaneous, and Other |
Summary of investments other than investments in related parties |
Cost | 370.2
Carrying Value | 400.6
Fair Value | 400.6
Exchange-traded funds |
Summary of investments other than investments in related parties |
Cost | 113.3
Carrying Value | 137.8
Fair Value | 137.8
Total common equity securities |
Summary of investments other than investments in related parties |
Cost | 483.5
Carrying Value | 538.4
Fair Value | 538.4
Other long-term investments |
Summary of investments other than investments in related parties |
Cost | 1,655.7
Carrying Value | 1,998.2
Fair Value | $ 1,998.2

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