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Investments - Additional Information (Details) - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2020 | Mar. 31, 2019
Schedule of Investments [Abstract] |  |
Realized gain (loss) on marketable securities | $ (0.3) | $ 0.8

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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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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- References No definition available. + Details
Name: | us-gaap_ScheduleOfInvestmentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration