XML 223 R141.htm IDEA: XBRL DOCUMENT
v3.22.4

Collaborative and Other Relationships - Summary of Activity Related to Sage Therapeutics (Details) - Sage Therapeutics - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Research and development |  |  |
Collaborative arrangements and non-collaborative arrangement transactions |  |  |
Expense incurred by the collaboration | $ 173.3 | $ 167.7 | $ 0.0
Expense reflected within statements of income | 86.7 | 83.8 | 0.0
Selling, general and administrative |  |  |
Collaborative arrangements and non-collaborative arrangement transactions |  |  |
Expense incurred by the collaboration | 109.9 | 36.4 | 0.0
Expense reflected within statements of income | $ 55.0 | $ 18.2 | $ 0.0

X
- Definition Expense incurred by the collaboration + References No definition available. + Details
Name: | biib_Expenseincurredbythecollaboration
Namespace Prefix: | biib_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Expense reflected within statements of income + References No definition available. + Details
Name: | biib_Expensereflectedwithinstatementsofincome
Namespace Prefix: | biib_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_ResearchAndDevelopmentExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=biib_SageTherapeuticsIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_SellingGeneralAndAdministrativeExpensesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |