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Held for Sale and Discontinued Operations - Narrative (Details) - USD ($) |  | 3 Months Ended |
--- | --- | --- | ---
Feb. 12, 2021 | Mar. 31, 2021 | Mar. 31, 2020 | Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |
Net gain from sale of discontinued operations, net of tax |  | $ 18,700,000 | $ 900,000 |
(Loss) gain on sale |  | (28,700,000) |  |
Corporate Aircraft |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |
Assets Held-for-sale, Not Part of Disposal Group |  |  |  | $ 1,700,000
Proceeds from sale of property held-for-sale | $ 2,100,000 |  |  |
Realized gain on sale of corporate aircraft |  | 500,000 |  |
Fresh Insurance Services Group Limited |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |
Proceeds from sale of other assets |  | 1,500,000 |  |
Discontinued Operations | Sirius Group |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |
Net gain from sale of discontinued operations, net of tax |  | 17,600,000 |  |
Contingent liability |  |  |  | $ 18,700,000
Discontinued Operations | Sirius Group | Foreign Currency Gain (Loss) |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |
Net gain from sale of discontinued operations, net of tax |  | $ 1,100,000 |  |

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