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Goodwill and Other Intangible Assets - Schedule of Goodwill and Other Intangible Assets Rollforward (Details) - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2021 | Mar. 31, 2020 | Dec. 31, 2020
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Goodwill, beginning balance | $ 525,500,000 |  |
Goodwill, impairment loss | (30,200,000) |  | $ 0
Amortization of other intangible assets | (9,200,000) | $ (5,100,000) |
Goodwill, ending balance | 613,400,000 |  | 525,500,000
Fresh Insurance Services Group Limited |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Proceeds from sale of other assets | 1,500,000 |  |
Goodwill |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Goodwill, beginning balance | 525,500,000 | 394,700,000 | 394,700,000
Acquisitions of businesses | 116,800,000 | 0 |
Goodwill, foreign currency translation gain (loss) | 1,500,000 | (2,500,000) |
Goodwill, impairment loss | (30,200,000) | 0 |
Measurement period adjustments | (200,000) | 200,000 |
Goodwill, ending balance | 613,400,000 | 392,400,000 | 525,500,000
Other Intangible Assets |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Other intangible assets (excluding goodwill), beginning balance | 256,900,000 | 260,000,000.0 | 260,000,000.0
Acquisitions of businesses | 175,700,000 | 0 |
Other intangible assets, foreign currency translation gain (loss) | 200,000 | (500,000) |
Measurement period adjustments | 0 | 0 |
Amortization of other intangible assets | (9,200,000) | (5,100,000) |
Other intangible assets (excluding goodwill), ending balance | 423,600,000 | 254,400,000 | 256,900,000
Total Goodwill and Other Intangible Assets |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |
Other intangible assets, gross (including goodwill), beginning balance | 782,400,000 | 654,700,000 | 654,700,000
Acquisitions of businesses | 292,500,000 | 0 |
Other intangible assets, foreign currency translation gain (loss) | 1,700,000 | (3,000,000.0) |
Goodwill, impairment loss | (30,200,000) | 0 |
Measurement period adjustments | (200,000) | 200,000 |
Amortization of other intangible assets | (9,200,000) | (5,100,000) |
Other intangible assets, gross (including goodwill), ending balance | $ 1,037,000,000.0 | $ 646,800,000 | $ 782,400,000

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