beatandraise : Equity Research with AI and ChatGPT on SEC Edgar

beatandraise.com

2.2.0.7 true Investments in Variable Interest Entities (Details) (USD $) 0616 - Disclosure - Investments in Variable Interest Entities (Details) true false false false 1 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 $ false 2 USD false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 $ 8 Investment in Variable Interest Entities (Textuals) [Abstract] 2 biib_InvestmentInVariableInterestEntitiesTextualsAbstract biib false na duration Investment in Variable Interest Entities Textuals Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string Investment in Variable Interest Entities Textuals Abstract. false 14 IPR&D charge recorded related to collaboration agreement 2 us-gaap_ResearchAndDevelopmentExpense us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 true true false false 319054000 319054000 false false false 2 true true false false 304055000 304055000 false false false 3 true true false false 957759000 957759000 false false false 4 true true false false 999986000 999986000 false false false xbrli:monetaryItemType monetary The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph g Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 2 -Paragraph 12, 13 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 86 -Paragraph 11, 12 false 19 Investment in biotechnology that determined to be unconsolidated variable interest entities 2 biib_InvestmentInBiotechnologyThatDeterminedToBeUnconsolidatedVariableInterestEntities biib false debit instant Investment in biotechnology that determined to be unconsolidated variable interest entities. false false false false false false false false false false false verboselabel false 1 false true false false 22700000 22700000 false false false 2 false false false false 0 0 false false false 3 false true false false 22700000 22700000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Investment in biotechnology that determined to be unconsolidated variable interest entities. No authoritative reference available. false 20 Receivable related to cost sharing arrangement 2 biib_ReceivableRelatedToCostSharingArrangement biib false debit instant Receivable related to cost sharing arrangement. false false false false false false false false false false false verboselabel false 1 false true false false 7900000 7900000 false false false 2 false false false false 0 0 false false false 3 false true false false 7900000 7900000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Receivable related to cost sharing arrangement. No authoritative reference available. false 21 Total joint venture assets 2 biib_TotalJointVentureAssets biib false debit instant This item represents disclosures of summarized financial information for joint ventures consolidated within our financial... false false false false false false false false false false false verboselabel false 1 false true false false 167100000 167100000 false false false 2 false false false false 0 0 false false false 3 false true false false 167100000 167100000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary This item represents disclosures of summarized financial information for joint ventures consolidated within our financial position and results of operations. No authoritative reference available. false 22 Total joint venture liabilities 2 biib_TotalJointVentureLiabilities biib false credit instant This item represents disclosures of summarized financial information for joint ventures consolidated within our financial... false false false false false false false false false false false verboselabel false 1 false true false false 75100000 75100000 false false false 2 false false false false 0 0 false false false 3 false true false false 75100000 75100000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary This item represents disclosures of summarized financial information for joint ventures consolidated within our financial position and results of operations. No authoritative reference available. false 23 Account receivable from ordinary course of business related to Joint Ventures 2 biib_AccountReceivableFromOrdinaryCourseOfBusinessRelatedToJointVentures biib false debit instant Account receivable from ordinary course of business related to Joint Ventures. false false false false false false false false false false false verboselabel false 1 false true false false 118500000 118500000 false false false 2 false false false false 0 0 false false false 3 false true false false 118500000 118500000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Account receivable from ordinary course of business related to Joint Ventures. No authoritative reference available. false 24 Cardiokine [Member] 0 na true na na No definition available. false true false false false false false false false false false http://biogenidec.com/role/investmentsinvariableinterestentitiesdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false false 5 USD true false false false Cardiokine [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseTwoMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 6 USD true false false false Cardiokine [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseTwoMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 7 USD true false false false Cardiokine [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseTwoMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 8 USD true false false false Cardiokine [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseTwoMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 25 Summary of activity related to collaborations 2 biib_SummaryOfActivityRelatedToCollaborationWithCompanyOneAbstract biib false na duration Summary of activity related to collaboration with company one. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string Summary of activity related to collaboration with company one. false 26 Milestone payments made to collaborative partner 2 biib_MilestonePaymentsMadeDuringPeriod biib false debit duration Milestone payments made during the period. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false true false false 20000000 20000000 false false false 3 false false false false 0 0 false false false 4 false true false false 20000000 20000000 false false false xbrli:monetaryItemType monetary Milestone payments made during the period. No authoritative reference available. false 27 Total development expense incurred by the collaboration 2 biib_TotalExpenseIncurredExcludingUpfrontAndMilestonePayments biib false debit duration Total development expense incurred excluding upfront and milestone payments. false false false false false false false false false false false verboselabel false 1 false true false false 10900000 10900000 false false false 2 false true false false 17200000 17200000 false false false 3 false true false false 47400000 47400000 false false false 4 false true false false 48500000 48500000 false false false xbrli:monetaryItemType monetary Total development expense incurred excluding upfront and milestone payments. No authoritative reference available. false 28 Biogen Idec's share of expense reflected within our consolidated statements of income 2 biib_TotalExpenseReflectedWithinStatementsOfIncome biib false debit duration Biogen Idec's share of development expense reflected within our consolidated statements of income. false false false false false false false false false false false verboselabel false 1 false true false false 9800000 9800000 false false false 2 false true false false 35500000 35500000 false false false 3 false true false false 42700000 42700000 false false false 4 false true false false 63700000 63700000 false false false xbrli:monetaryItemType monetary Biogen Idec's share of development expense reflected within our consolidated statements of income. No authoritative reference available. false 29 Collaboration expense allocated to noncontrolling interests, net of tax 2 biib_CollaborationExpenseAllocatedToNoncontrollingInterestsNetOfTax biib false debit duration Collaboration expense allocated to noncontrolling interests, net of tax. false false false false false false false false false false false verboselabel false 1 false true false false 1100000 1100000 false false false 2 false true false false 1700000 1700000 false false false 3 false true false false 4700000 4700000 false false false 4 false true false false 4800000 4800000 false false false xbrli:monetaryItemType monetary Collaboration expense allocated to noncontrolling interests, net of tax. No authoritative reference available. false 31 Investment in Variable Interest Entities (Textuals) [Abstract] 2 biib_InvestmentInVariableInterestEntitiesTextualsAbstract biib false na duration Investment in Variable Interest Entities Textuals Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string Investment in Variable Interest Entities Textuals Abstract. false 33 Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration agreement 2 biib_RemainingPotentialDevelopmentMilestonePaymentsAndRoyaltiesOnCommercialSalesUnderTermsOfCollaborationAgreement biib false credit duration Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 100000000 100000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration agreement. No authoritative reference available. false 40 Percentage of funding for R&D cost required in support of the collaboration agreement 2 biib_ResearchAndDevelopmentCostInSupportOfCollaborationAgreement biib false na duration Research and development cost in support of the collaboration agreement. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0.9 0.9 false false false 4 false false false false 0 0 false false false us-types:percentItemType pure Research and development cost in support of the collaboration agreement. No authoritative reference available. false 41 Milestone payments to be paid in the future to collaborative partner 2 biib_MilestonePaymentsMadeDuringPeriod biib false debit duration Milestone payments made during the period. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false true false false 20000000 20000000 false false false 3 false false false false 0 0 false false false 4 false true false false 20000000 20000000 false false false xbrli:monetaryItemType monetary Milestone payments made during the period. No authoritative reference available. false 47 Knopp [Member] 0 na true na na No definition available. false true false false false false false false false false false http://biogenidec.com/role/investmentsinvariableinterestentitiesdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false false 9 USD true false false false Knopp [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseThreeMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 10 USD true false false false Knopp [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseThreeMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ na No definition available. No authoritative reference available. false 48 Summary of activity related to collaborations 2 biib_SummaryOfActivityRelatedToCollaborationWithCompanyOneAbstract biib false na duration Summary of activity related to collaboration with company one. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string Summary of activity related to collaboration with company one. false 50 Total development expense incurred by the collaboration 2 biib_TotalExpenseIncurredExcludingUpfrontAndMilestonePayments biib false debit duration Total development expense incurred excluding upfront and milestone payments. false false false false false false false false false false false verboselabel false 1 false true false false 1000000 1000000 false false false 2 false false false false 0 0 false false false 3 false true false false 1000000 1000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total development expense incurred excluding upfront and milestone payments. No authoritative reference available. false 51 Biogen Idec's share of expense reflected within our consolidated statements of income 2 biib_TotalExpenseReflectedWithinStatementsOfIncome biib false debit duration Biogen Idec's share of development expense reflected within our consolidated statements of income. false false false false false false false false false false false verboselabel false 1 false true false false 27400000 27400000 false false false 2 false false false false 0 0 false false false 3 false true false false 27400000 27400000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Biogen Idec's share of development expense reflected within our consolidated statements of income. No authoritative reference available. false 53 Total upfront and reimbursent payment made to collaborative partner 2 biib_UpfrontAndReimbursementPaymentMadeToCollaborativePartner biib false debit duration Total upfront and reimbursent payment made to collaborative partner. false false false false false false false false false false false verboselabel false 1 false true false false 26400000 26400000 false false false 2 false false false false 0 0 false false false 3 false true false false 26400000 26400000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total upfront and reimbursent payment made to collaborative partner. No authoritative reference available. false 54 Investment in Variable Interest Entities (Textuals) [Abstract] 2 biib_InvestmentInVariableInterestEntitiesTextualsAbstract biib false na duration Investment in Variable Interest Entities Textuals Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string Investment in Variable Interest Entities Textuals Abstract. false 55 Total upfront and reimbursent payment made to collaborative partner 2 biib_UpfrontAndReimbursementPaymentMadeToCollaborativePartner biib false debit duration Total upfront and reimbursent payment made to collaborative partner. false false false false false false false false false false false verboselabel false 1 false true false false 26400000 26400000 false false false 2 false false false false 0 0 false false false 3 false true false false 26400000 26400000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total upfront and reimbursent payment made to collaborative partner. No authoritative reference available. false 56 Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration agreement 2 biib_RemainingPotentialDevelopmentMilestonePaymentsAndRoyaltiesOnCommercialSalesUnderTermsOfCollaborationAgreement biib false credit duration Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 265000000 265000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration agreement. No authoritative reference available. false 57 Minimum number of years of product term from the first commercial sales 2 biib_MinimumNumberOfYearsOfProductTermFromFirstCommercialSales biib false na duration Minimum number of years of product term from first commercial sales. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 10 10 false false false 4 false false false false 0 0 false false false xbrli:integerItemType integer Minimum number of years of product term from first commercial sales. No authoritative reference available. false 58 Purchase of Class B common shares of Knopp 2 biib_PurchaseOfClassBCommonSharesInVariableInterestEntities biib false na duration Purchase of Class B Common Shares in Variable Interest Entities. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0.3 0.3 false false false 4 false false false false 0 0 false false false us-types:percentItemType pure Purchase of Class B Common Shares in Variable Interest Entities. No authoritative reference available. false 59 Purchase consideration for Knopp 2 biib_PurchaseConsiderationForVariableInterestEntities biib false debit duration Purchase Consideration for Variable Interest Entities. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 60000000 60000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Purchase Consideration for Variable Interest Entities. No authoritative reference available. false 60 IPR&D charge recorded related to collaboration agreement 2 us-gaap_ResearchAndDevelopmentExpense us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 205000000 205000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph g Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 2 -Paragraph 12, 13 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 86 -Paragraph 11, 12 false 61 Discount rate to value Dexpramipexole 2 biib_DiscountRateToValueAssets biib false na duration Discount rate to value assets. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0.14 0.14 false false false 4 false false false false 0 0 false false false us-types:percentItemType pure Discount rate to value assets. No authoritative reference available. false 62 IPR&D charge allocated to noncontrolling interest 2 biib_AllocatedResearchAndDevelopmentChargeToNoncontrollingInterest biib false debit duration Allocated research and development charge to the noncontrolling interest. false false false false false false false false false false false verboselabel false 1 false true false false 145000000 145000000 false false false 2 false false false false 0 0 false false false 3 false true false false 145000000 145000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Allocated research and development charge to the noncontrolling interest. No authoritative reference available. false 70 Neurimmune [Member] 0 na true na na No definition available. false true false false false false false false false false false http://biogenidec.com/role/investmentsinvariableinterestentitiesdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false false 11 USD true false false false Neurimmune [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseOneMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 12 USD true false false false Neurimmune [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseOneMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 13 USD true false false false Neurimmune [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseOneMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 14 USD true false false false Neurimmune [Member] us-gaap_VariableInterestByInterestTypeAxis xbrldi http://xbrl.org/2006/xbrldi biib_VariableInterestEnterpriseOneMember us-gaap_VariableInterestByInterestTypeAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 71 Summary of activity related to collaborations 2 biib_SummaryOfActivityRelatedToCollaborationWithCompanyOneAbstract biib false na duration Summary of activity related to collaboration with company one. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string Summary of activity related to collaboration with company one. false 72 Milestone payments made to collaborative partner 2 biib_MilestonePaymentsMadeDuringPeriod biib false debit duration Milestone payments made during the period. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 7500000 7500000 false false false xbrli:monetaryItemType monetary Milestone payments made during the period. No authoritative reference available. false 73 Total development expense incurred by the collaboration 2 biib_TotalExpenseIncurredExcludingUpfrontAndMilestonePayments biib false debit duration Total development expense incurred excluding upfront and milestone payments. false false false false false false false false false false false verboselabel false 1 false true false false 2400000 2400000 false false false 2 false true false false 1900000 1900000 false false false 3 false true false false 12800000 12800000 false false false 4 false true false false 5500000 5500000 false false false xbrli:monetaryItemType monetary Total development expense incurred excluding upfront and milestone payments. No authoritative reference available. false 74 Biogen Idec's share of expense reflected within our consolidated statements of income 2 biib_TotalExpenseReflectedWithinStatementsOfIncome biib false debit duration Biogen Idec's share of development expense reflected within our consolidated statements of income. false false false false false false false false false false false verboselabel false 1 false true false false 2400000 2400000 false false false 2 false true false false 1900000 1900000 false false false 3 false true false false 12800000 12800000 false false false 4 false true false false 13000000 13000000 false false false xbrli:monetaryItemType monetary Biogen Idec's share of development expense reflected within our consolidated statements of income. No authoritative reference available. false 77 Investment in Variable Interest Entities (Textuals) [Abstract] 2 biib_InvestmentInVariableInterestEntitiesTextualsAbstract biib false na duration Investment in Variable Interest Entities Textuals Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string Investment in Variable Interest Entities Textuals Abstract. false 79 Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration agreement 2 biib_RemainingPotentialDevelopmentMilestonePaymentsAndRoyaltiesOnCommercialSalesUnderTermsOfCollaborationAgreement biib false credit duration Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 360000000 360000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration agreement. No authoritative reference available. false 86 Percentage of funding for R&D cost required in support of the collaboration agreement 2 biib_ResearchAndDevelopmentCostInSupportOfCollaborationAgreement biib false na duration Research and development cost in support of the collaboration agreement. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 1 1 false false false 4 false false false false 0 0 false false false us-types:percentItemType pure Research and development cost in support of the collaboration agreement. No authoritative reference available. false 87 Milestone payments to be paid in the future to collaborative partner 2 biib_MilestonePaymentsMadeDuringPeriod biib false debit duration Milestone payments made during the period. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 true true false false 7500000 7500000 false false false xbrli:monetaryItemType monetary Milestone payments made during the period. No authoritative reference available. false 4 40 false NoRounding UnKnown UnKnown false true