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Income Taxes (Details Textual) - USD ($) $ in Millions | Mar. 31, 2021 | Dec. 31, 2020
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Income Tax Contingency [Line Items] |  |
Decrease in unrecognized tax benefits is reasonably possible |  | $ 25.0
TECFIDERA |  |
Income Tax Contingency [Line Items] |  |
Deferred tax assets, decrease in value | $ 1,700.0 |
Deferred tax liabilities, decrease in value | $ 1,600.0 |

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- Definition Deferred Tax Liabilities, Value, Reduction in Value + References No definition available. + Details
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- Definition Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (d)(3) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
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- Details
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