XML 166 R111.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Collaborative and Other Relationships (Details 1) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Collaborative arrangements and non-collaborative arrangement transactions |  |  |  |  |  |  |  |  |  |  |
Revenues | $ 2,872.0 | $ 2,955.8 | $ 2,894.2 | $ 2,726.8 | $ 2,839.3 | $ 2,777.9 | $ 2,591.6 | $ 2,555.0 | $ 11,448.8 | $ 10,763.8 | $ 9,703.3
AbbVie |  |  |  |  |  |  |  |  |  |  |
Collaborative arrangements and non-collaborative arrangement transactions |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  | 6.1 |  |
Total expense incurred by collaboration |  |  |  |  |  |  |  |  | 50.0 |  |
Co-promotion profits and losses |  |  |  |  |  |  |  |  | 43.9 |  |
Biogen's share of co-promotion losses |  |  |  |  |  |  |  |  | $ 21.9 |  |

X
- Definition Co-promotion profits and losses + References No definition available. + Details
Name: | biib_Copromotionprofitsandlosses
Namespace Prefix: | biib_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition Share of co promotion profits. + References No definition available. + Details
Name: | biib_ShareOfCoPromotionProfits
Namespace Prefix: | biib_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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