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Commitments and Contingencies (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019 | Dec. 31, 2019
Loss Contingencies [Line Items] |  |  |  |  |
Net gain from sale of discontinued operations, net of tax | $ (0.7) | $ 0.9 | $ (0.8) | $ 1.6 |
Sirius Group | Swedish Tax Authority |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |
Contingent liability | 17.2 |  | 17.2 |  | $ 16.5
Sirius Group | Swedish Tax Authority | Sirius Group |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |
Change in contingent liability | $ (0.7) |  | $ (0.7) |  |

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