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Goodwill and Other Intangible Assets - Schedule of Goodwill and Other Intangible Assets Rollforward (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2022 | Mar. 31, 2021 | Dec. 31, 2021
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Goodwill, beginning balance | $ 645.5 |  |
Amortization of other intangible assets | (10.1) | $ (9.2) |
Loss on assets held for sale | (30.2) |  | $ (30.2)
Goodwill, ending balance | 641.4 |  | 645.5
Fresh Insurance Services Group Limited |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Proceeds from sale of other assets |  | 1.5 |
Goodwill |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Goodwill, beginning balance | 645.5 | 525.5 | 525.5
Measurement period adjustments | 0.0 | (0.2) |
Amortization of other intangible assets | 0.0 | 0.0 |
Loss on assets held for sale | 0.0 | (30.2) |
Foreign currency translation | (4.1) | 1.5 |
Goodwill, ending balance | 641.4 | 613.4 | 645.5
Goodwill | Other |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Measurement period adjustments |  | 0.2 |
Goodwill | Ark |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Goodwill acquired | 0.0 | 116.8 |
Other |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Other intangible assets (excluding goodwill), beginning balance | 420.4 | 256.9 | 256.9
Measurement period adjustments | 0.0 | 0.0 |
Amortization of other intangible assets | (10.1) | (9.2) |
Loss on assets held for sale | 0.0 | 0.0 |
Foreign currency translation | (0.2) | 0.2 |
Other intangible assets (excluding goodwill), ending balance | 410.1 | 423.6 | 420.4
Other | Ark |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Intangible assets acquired | 0.0 | 175.7 |
Total Goodwill and Other Intangible Assets |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Other intangible assets, gross (including goodwill), beginning balance | 1,065.9 | 782.4 | 782.4
Measurement period adjustments | 0.0 | (0.2) |
Amortization of other intangible assets | (10.1) | (9.2) |
Loss on assets held for sale | 0.0 | (30.2) |
Foreign currency translation | (4.3) | 1.7 |
Other intangible assets, gross (including goodwill), ending balance | 1,051.5 | 1,037.0 | $ 1,065.9
Total Goodwill and Other Intangible Assets | Ark |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Goodwill and other intangible assets acquired | $ 0.0 | $ 292.5 |

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