XML 109 R84.htm IDEA: XBRL DOCUMENT
v3.23.1

Collaborative and Other Relationships - Summary of Activity Related to Sangamo Therapeutics (Details) - Sangamo Therapeutics, Inc. Agreement - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Collaborative arrangements and non-collaborative arrangement transactions |  |
Term of collaboration agreement | 5 years |
Research and development |  |
Collaborative arrangements and non-collaborative arrangement transactions |  |
Expense incurred by the collaboration | $ 5.1 | $ 8.3
Expense reflected within statements of income | $ 2.3 | $ 5.5

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 Term of collaboration agreement + References No definition available. + Details
Name: | biib_Termofcollaborationagreement
Namespace Prefix: | biib_
Data Type: | xbrli:durationItemType
Balance Type: | na
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_TypeOfArrangementAxis=biib_SangamoTherapeuticsIncAaAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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