XML 137 R58.htm IDEA: XBRL DOCUMENT v2.4.1.9
Acquisitions (Details) (USD $)
12 Months Ended 3 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Jun. 30, 2013
Mar. 31, 2012
Apr. 02, 2013
Mar. 08, 2012
Mar. 07, 2012
Business Acquisition                
Acquisition of TYSABRI rights $ 0us-gaap_PaymentsToAcquireIntangibleAssets $ 3,262,719,000us-gaap_PaymentsToAcquireIntangibleAssets $ 0us-gaap_PaymentsToAcquireIntangibleAssets          
Deferred revenue 120,900,000us-gaap_DeferredRevenueCurrent 172,700,000us-gaap_DeferredRevenueCurrent            
Contingent consideration obligation 0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases 0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases            
Total purchase price allocated to goodwill 1,760,249,000us-gaap_Goodwill 1,232,916,000us-gaap_Goodwill 1,201,300,000us-gaap_Goodwill          
Other goodwill adjustments 0us-gaap_GoodwillOtherChanges              
TYSABRI product                
Business Acquisition                
Acquisition of TYSABRI rights       3,250,000,000us-gaap_PaymentsToAcquireIntangibleAssets
/ us-gaap_BusinessAcquisitionAxis
= biib_TysabriProductMember
       
Deferred revenue           84,400,000us-gaap_DeferredRevenueCurrent
/ us-gaap_BusinessAcquisitionAxis
= biib_TysabriProductMember
   
Net intangible asset           3,178,300,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles
/ us-gaap_BusinessAcquisitionAxis
= biib_TysabriProductMember
   
Estimated life, (In Years)       17 years        
Future contingent payment for the first 12 months           12.00%biib_FutureContingentPaymentForFirst12Months
/ us-gaap_BusinessAcquisitionAxis
= biib_TysabriProductMember
   
Future contingent payment for annual worldwide net sales up to $2.0 billion           18.00%biib_FutureContingentPaymentForAnnualWorldwideNetSalesUpTo20Billion
/ us-gaap_BusinessAcquisitionAxis
= biib_TysabriProductMember
   
Future contingent payment threshold           2,000,000,000biib_FutureContingentPaymentThreshold
/ us-gaap_BusinessAcquisitionAxis
= biib_TysabriProductMember
   
Future contingent payment for annual worldwide net sales that exceed $2.0 billion           25.00%biib_FutureContingentPaymentForAnnualWorldwideNetSalesThatExceed20Billion
/ us-gaap_BusinessAcquisitionAxis
= biib_TysabriProductMember
   
Stromedix, Inc.                
Business Acquisition                
Cash portion of consideration         75,000,000us-gaap_PaymentsToAcquireBusinessesGross
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
     
Maximum contingent consideration in the form of development and approval milestones 419,000,000us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
          487,500,000us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
 
Contingent consideration obligation         122,200,000us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
     
Total purchase price allocated to IPR&D             219,200,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
 
Total purchase price allocated to goodwill             48,200,000us-gaap_Goodwill
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
 
Other goodwill adjustments   (4,100,000)us-gaap_GoodwillOtherChanges
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
           
Percentage of equity interest to the portion of total capital stock               5.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
Recognized gain     9,000,000biib_GainLossRecognizedDuringAcquisitionRelatingToPreExistingEquityInterest
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
         
STX One Hundred | Stromedix, Inc.                
Business Acquisition                
Maximum contingent consideration in the form of development and approval milestones             $ 275,000,000us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh
/ us-gaap_BusinessAcquisitionAxis
= biib_StromedixMember
/ us-gaap_ProductOrServiceAxis
= biib_StxOneHundredMember