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Investment Securities - Mortgage-backed Asset Securities (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Total mortgage and asset-backed securities and collateralized loan obligations |  |
Investment securities |  |
Fixed maturity investments, at fair value | $ 610.6 | $ 598.5
Mortgage and asset-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 373.9 | 389.4
Total mortgage-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 370.0 | 366.4
Total mortgage-backed securities | Total non-agency |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.4 | 0.2
Total mortgage-backed securities | Total agency |  |
Investment securities |  |
Fixed maturity investments, at fair value | 369.6 | 366.2
Total mortgage-backed securities | FNMA |  |
Investment securities |  |
Fixed maturity investments, at fair value | 198.3 | 198.8
Total mortgage-backed securities | FHLMC |  |
Investment securities |  |
Fixed maturity investments, at fair value | 147.1 | 137.2
Total mortgage-backed securities | GNMA |  |
Investment securities |  |
Fixed maturity investments, at fair value | 24.2 | 30.2
Total mortgage-backed securities | Commercial |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.4 | 0.0
Total mortgage-backed securities | Residential |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.2
Total other asset-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 3.9 | 23.0
Total other asset-backed securities | Vehicle receivables |  |
Investment securities |  |
Fixed maturity investments, at fair value | 1.7 | 17.2
Total other asset-backed securities | Credit card receivables |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.2 | 3.3
Total other asset-backed securities | Other |  |
Investment securities |  |
Fixed maturity investments, at fair value | 2.0 | 2.5
Collateralized loan obligations |  |
Investment securities |  |
Fixed maturity investments, at fair value | 236.7 | 209.1
Level 2 | Total mortgage and asset-backed securities and collateralized loan obligations |  |
Investment securities |  |
Fixed maturity investments, at fair value | 610.6 | 598.5
Level 2 | Mortgage and asset-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 373.9 | 389.4
Level 2 | Total mortgage-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 370.0 | 366.4
Level 2 | Total mortgage-backed securities | Total non-agency |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.4 | 0.2
Level 2 | Total mortgage-backed securities | Total agency |  |
Investment securities |  |
Fixed maturity investments, at fair value | 369.6 | 366.2
Level 2 | Total mortgage-backed securities | FNMA |  |
Investment securities |  |
Fixed maturity investments, at fair value | 198.3 | 198.8
Level 2 | Total mortgage-backed securities | FHLMC |  |
Investment securities |  |
Fixed maturity investments, at fair value | 147.1 | 137.2
Level 2 | Total mortgage-backed securities | GNMA |  |
Investment securities |  |
Fixed maturity investments, at fair value | 24.2 | 30.2
Level 2 | Total mortgage-backed securities | Commercial |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.4 | 0.0
Level 2 | Total mortgage-backed securities | Residential |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.2
Level 2 | Total other asset-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 3.9 | 23.0
Level 2 | Total other asset-backed securities | Vehicle receivables |  |
Investment securities |  |
Fixed maturity investments, at fair value | 1.7 | 17.2
Level 2 | Total other asset-backed securities | Credit card receivables |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.2 | 3.3
Level 2 | Total other asset-backed securities | Other |  |
Investment securities |  |
Fixed maturity investments, at fair value | 2.0 | 2.5
Level 2 | Collateralized loan obligations |  |
Investment securities |  |
Fixed maturity investments, at fair value | 236.7 | 209.1
Level 3 | Total mortgage and asset-backed securities and collateralized loan obligations |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Mortgage and asset-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total mortgage-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total mortgage-backed securities | Total non-agency |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total mortgage-backed securities | Total agency |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total mortgage-backed securities | FNMA |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total mortgage-backed securities | FHLMC |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total mortgage-backed securities | GNMA |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total mortgage-backed securities | Commercial |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total mortgage-backed securities | Residential |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total other asset-backed securities |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total other asset-backed securities | Vehicle receivables |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total other asset-backed securities | Credit card receivables |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Total other asset-backed securities | Other |  |
Investment securities |  |
Fixed maturity investments, at fair value | 0.0 | 0.0
Level 3 | Collateralized loan obligations |  |
Investment securities |  |
Fixed maturity investments, at fair value | $ 0.0 | $ 0.0

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