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Held for Sale and Discontinued Operations - Narrative (Details) £ in Millions, $ in Millions |  |  |  |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | ---
Sep. 17, 2021 USD ($) | Apr. 12, 2021 USD ($) | Apr. 12, 2021 GBP (£) | Feb. 12, 2021 USD ($) | Aug. 20, 2020 USD ($) | Mar. 31, 2021 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of discontinued operations |  |  |  |  |  |  | $ 18.7 | $ (2.3) | $ 0.8 |
Total assets |  |  |  |  |  |  | 7,000.7 | 4,831.4 |  |
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Corporate Aircraft |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Proceeds from sale of property held-for-sale |  |  |  | $ 2.1 |  |  |  |  |  |
Gain on sale of aircraft |  |  |  | $ 0.5 |  |  |  |  |  |
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Connecticut |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Proceeds from sale of property held-for-sale |  |  |  |  | $ 2.3 |  |  |  |  |
Realized gain losses on sales of other real estate |  |  |  |  |  |  |  | (0.1) |  |
Proceeds from sale of land | $ 0.7 |  |  |  |  |  |  |  |  |
Loss on sale of land | $ 0.1 |  |  |  |  |  |  |  |  |
Disposal Group, Held-for-sale, Not Discontinued Operations | Corporate Aircraft |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Assets held for sale |  |  |  |  |  |  |  | 1.7 |  |
Disposal Group, Held-for-sale, Not Discontinued Operations | Connecticut |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Assets held for sale |  |  |  |  |  |  |  | 0.7 |  |
Sirius Group |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of discontinued operations |  |  |  |  |  |  |  |  |  | $ 17.3
Sirius Group | Discontinued Operations, Disposed of by Sale |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of discontinued operations |  |  |  |  |  |  | 17.6 |  |  |
Discontinued operations, liability |  |  |  |  |  |  |  | 18.7 |  |
Increase in discontinued operations liability |  |  |  |  |  |  |  | $ 2.2 |  |
Sirius Group | Discontinued Operations, Disposed of by Sale | Foreign Currency Gain (Loss) |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of discontinued operations |  |  |  |  |  |  | 1.1 |  |  |
Fresh Insurance Services Group Limited | Disposal Group, Disposed of by Sale, Not Discontinued Operations |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Proceeds from sale of business |  | $ 1.5 | £ 1.1 |  |  |  |  |  |  |
Fresh Insurance Services Group Limited | Disposal Group, Held-for-sale, Not Discontinued Operations |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Loss on sale |  |  |  |  |  | $ 28.7 | (28.7) |  |  |
Other Operations | Disposal Group, Held-for-sale, Not Discontinued Operations |  |  |  |  |  |  |  |  |  |
Discontinued Operations |  |  |  |  |  |  |  |  |  |
Total assets |  |  |  |  |  |  | $ 16.1 |  |  |

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