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Third-Party Reinsurance - Effects of Reinsurance (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Earned premiums: |  |  |
Net earned premiums | $ 1,076.7 | $ 664.2 | $ 22.8
Ark |  |  |
Written premiums: |  |  |
Direct | 1,452.0 | 1,058.7 |
Ceded | (256.8) | (199.6) |
Net written premiums | 1,195.2 | 859.1 |
Earned premiums: |  |  |
Direct | 1,324.2 | 886.4 |
Ceded | (280.8) | (249.1) |
Net earned premiums | 1,043.4 | 637.3 |
Losses and LAE: |  |  |
Gross | 814.9 | 442.9 |
Ceded | (278.5) | (128.1) |
Net Losses and LAE | $ 536.4 | $ 314.8 |

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