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Other Investments - Investments without Readily Determinable Fair Value (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Investments, All Other Investments [Abstract] |  |  |
Cost | $ 8.5 | $ 8.5 |
Cumulative unrealized gains | 41.9 | 5.3 |
Carrying amount | 50.4 | $ 13.8 | $ 0.0
Upward adjustments | $ 36.6 |  |

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