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Investments - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Schedule of Investments [Abstract] |  |  |  |
Realized gain (loss) on marketable securities | $ 0.2 | $ 4.5 | $ 2.0 | $ 4.2

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- Definition Amount of realized gain (loss) on investment in debt and equity securities. + References No definition available. + Details
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- References No definition available. + Details
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