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v3.21.1

Intangible Assets and Goodwill (Details) - USD ($) | 3 Months Ended
--- | ---
Mar. 31, 2021 | Dec. 31, 2020 | Mar. 31, 2020
Finite-Lived Intangible Assets [Line Items] |  |  |
Impairment of Intangible Assets (Excluding Goodwill) | $ 0 |  | $ 0
Intangible assets |  |  |
Contingent consideration impairment | 33,800,000 |  | 4,600,000
Total intangible assets, gross | 8,178,400,000 | $ 8,220,800,000 |
Accumulated Amortization | (5,190,300,000) | (5,136,500,000) |
Intangible assets, net | 2,988,100,000 | 3,084,300,000 |
Amortization and impairment of acquired intangible assets | 98,100,000 |  | 71,500,000
Expected future amortization expense, 2019 (remaining three months) | 165,000,000.0 |  |
Expected future amortization expense, 2020 | 215,000,000.0 |  |
Expected future amortization expense, 2021 | 215,000,000.0 |  |
Expected future amortization expense, 2022 | 225,000,000.0 |  |
Expected future amortization expense, 2023 | 220,000,000.0 |  |
Expected future amortization expense, 2024 | 200,000,000.0 |  |
Out-licensed patents |  |  |
Intangible assets |  |  |
Cost | 7,394,300,000 | 7,394,300,000 |
Net | 2,204,000,000.0 | 2,257,800,000 |
Accumulated Amortization | $ 5,190,300,000 | 5,136,500,000 |
Out-licensed patents | Minimum |  |  |
Intangible assets |  |  |
Estimated life, (in years) | 13 years |  |
Out-licensed patents | Maximum |  |  |
Intangible assets |  |  |
Estimated life, (in years) | 23 years |  |
Developed technology | Minimum |  |  |
Intangible assets |  |  |
Estimated life, (in years) | 15 years |  |
Developed technology | Maximum |  |  |
Intangible assets |  |  |
Estimated life, (in years) | 28 years |  |
Acquired and in-licensed rights and patents | Minimum |  |  |
Intangible assets |  |  |
Estimated life, (in years) | 4 years |  |
Acquired and in-licensed rights and patents | Maximum |  |  |
Intangible assets |  |  |
Estimated life, (in years) | 18 years |  |
In Process Research and Development |  |  |
Intangible assets |  |  |
Indefinite lived intangible assets useful life | Indefinite until commercialization |  |
Cost and Net | $ 720,100,000 | 762,500,000 |
Accumulated Amortization | $ 0 | 0 |
Trademarks and Trade Names |  |  |
Intangible assets |  |  |
Indefinite lived intangible assets useful life | Indefinite |  |
Cost and Net | $ 64,000,000.0 | 64,000,000.0 |
Accumulated Amortization | 0 | 0 |
TGN [Member] | In Process Research and Development |  |  |
Intangible assets |  |  |
Cost and Net | 135,100,000 |  |
Vixotrigine |  |  |
Intangible assets |  |  |
Amortization and impairment of acquired intangible assets | $ 44,300,000 |  | $ 0
BIIB111 | Nightstar |  |  |
Intangible assets |  |  |
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill) |  | $ 115,000,000.0 |

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