Litigation	9 Months Ended
Sep. 30, 2014
Loss Contingency, Information about Litigation Matters [Abstract]
Litigation	Litigation ’755 Patent Litigation On May 27, 2010, Bayer Healthcare Pharmaceuticals Inc. (Bayer) filed a lawsuit against us in the U.S. District Court for the District of New Jersey seeking a declaratory judgment that they do not infringe our U.S. Patent No. 7,588,755 (’755 Patent), which claims the use of interferon beta for immunomodulation or treating a viral condition, viral disease, cancers or tumors, and that the patent is invalid and seeking monetary relief in the form of attorneys' fees, costs and expenses. On May 28, 2010, Biogen Idec MA Inc. (BIMA) filed a lawsuit in the U.S. District Court for the District of New Jersey alleging infringement of the ’755 Patent by EMD Serono, Inc. (manufacturer, marketer and seller of REBIF), Pfizer, Inc. (co-marketer of REBIF), Bayer (manufacturer, marketer and seller of BETASERON and manufacturer of EXTAVIA), and Novartis Pharmaceuticals Corp. (marketer and seller of EXTAVIA) and seeking monetary damages, including lost profits and royalties. The court has consolidated the two lawsuits, and we refer to the two actions as the “Consolidated ’755 Patent Actions”. Bayer, Pfizer, Novartis and EMD Serono have all filed counterclaims in the Consolidated ’755 Patent Actions seeking declaratory judgments of patent invalidity and non-infringement, and seeking monetary relief in the form of costs and attorneys' fees, and EMD Serono and Bayer have each filed a counterclaim seeking a declaratory judgment that the ’755 Patent is unenforceable based on alleged inequitable conduct. Bayer has also amended its complaint to seek such a declaration. No trial date has been set. Italian National Medicines Agency In the fourth quarter of 2011, Biogen Idec Italia SRL received notice from the Italian National Medicines Agency (Agenzia Italiana del Farmaco or AIFA) that sales of TYSABRI after mid-February 2009 exceeded a reimbursement limit established pursuant to a Price Determination Resolution (Price Resolution) granted by AIFA in December 2006. On December 23, 2011, we filed an appeal in the Regional Administrative Tribunal of Lazio (Il Tribunale Amministrativo Regionale per il Lazio) in Rome seeking a ruling that the reimbursement limit in the Price Resolution should apply as written to only “the first 24 months” of TYSABRI sales, which ended in mid-February 2009. The appeal is still pending. Earlier this year AIFA approved a resolution affirming that that there is no reimbursement limit from and after February 2013. AIFA and Biogen Idec Italia SRL are discussing a possible resolution for the period from mid-February 2009 through January 2013. Average Manufacturer Price Litigation On September 6, 2011, we and several other pharmaceutical companies were served with a complaint originally filed under seal on October 28, 2008 in the United States District Court for the Eastern District of Pennsylvania by Ronald Streck on behalf of himself and the United States, 24 states and the District of Columbia (collectively the “States”). The complaint alleges that Biogen Idec violated the False Claims Act, 31 U.S.C. § 3729 et seq. and local statutory counterparts by under reporting Average Manufacturer Price (AMP) information to the Centers for Medicare and Medicaid Services. The United States and the States have declined to intervene. We believe we have good and valid defenses. We have not formed an opinion that an unfavorable outcome under the remaining claims is either “probable” or “remote”. Government Matters We have learned that state and federal governmental authorities are investigating our sales and promotional practices and have received related subpoenas. We have also received a subpoena from the federal government for documents relating to our relationship with certain pharmacy benefit managers. We are cooperating with the government in these matters. Qui Tam Litigation In August, 2012, we learned that a relator, on behalf of the United States and certain states, filed a suit under seal on February 17, 2011 against us, Elan Corporation, plc, and Elan Pharmaceuticals, Inc. in the United States District Court for the Western District of Virginia. We have neither seen nor been served with the complaint, but understand that it was filed under the Federal False Claims Act. Product Liability and Other Legal Proceedings We are also involved in product liability claims and other legal proceedings generally incidental to our normal business activities. While the outcome of any of these proceedings cannot be accurately predicted, we do not believe the ultimate resolution of any of these existing matters would have a material adverse effect on our business or financial condition.

Litigation

’755 Patent Litigation

On May 27, 2010, Bayer Healthcare Pharmaceuticals Inc. (Bayer) filed a lawsuit against us in the U.S. District Court for the District of New Jersey seeking a declaratory judgment that they do not infringe our U.S. Patent No. 7,588,755 (’755 Patent), which claims the use of interferon beta for immunomodulation or treating a viral condition, viral disease, cancers or tumors, and that the patent is invalid and seeking monetary relief in the form of attorneys' fees, costs and expenses. On May 28, 2010, Biogen Idec MA Inc. (BIMA) filed a lawsuit in the U.S. District Court for the District of New Jersey alleging infringement of the ’755 Patent by EMD Serono, Inc. (manufacturer, marketer and seller of REBIF), Pfizer, Inc. (co-marketer of REBIF), Bayer (manufacturer, marketer and seller of BETASERON and manufacturer of EXTAVIA), and Novartis Pharmaceuticals Corp. (marketer and seller of EXTAVIA) and seeking monetary damages, including lost profits and royalties. The court has consolidated the two lawsuits, and we refer to the two actions as the “Consolidated ’755 Patent Actions”.

Bayer, Pfizer, Novartis and EMD Serono have all filed counterclaims in the Consolidated ’755 Patent Actions seeking declaratory judgments of patent invalidity and non-infringement, and seeking monetary relief in the form of costs and attorneys' fees, and EMD Serono and Bayer have each filed a counterclaim seeking a declaratory judgment that the ’755 Patent is unenforceable based on alleged inequitable conduct. Bayer has also amended its complaint to seek such a declaration. No trial date has been set.

Italian National Medicines Agency

In the fourth quarter of 2011, Biogen Idec Italia SRL received notice from the Italian National Medicines Agency (Agenzia Italiana del Farmaco or AIFA) that sales of TYSABRI after mid-February 2009 exceeded a reimbursement limit established pursuant to a Price Determination Resolution (Price Resolution) granted by AIFA in December 2006. On December 23, 2011, we filed an appeal in the Regional Administrative Tribunal of Lazio (Il Tribunale Amministrativo Regionale per il Lazio) in Rome seeking a ruling that the reimbursement limit in the Price Resolution should apply as written to only “the first 24 months” of TYSABRI sales, which ended in mid-February 2009. The appeal is still pending. Earlier this year AIFA approved a resolution affirming that that there is no reimbursement limit from and after February 2013. AIFA and Biogen Idec Italia SRL are discussing a possible resolution for the period from mid-February 2009 through January 2013.

Average Manufacturer Price Litigation

On September 6, 2011, we and several other pharmaceutical companies were served with a complaint originally filed under seal on October 28, 2008 in the United States District Court for the Eastern District of Pennsylvania by Ronald Streck on behalf of himself and the United States, 24 states and the District of Columbia (collectively the “States”). The complaint alleges that Biogen Idec violated the False Claims Act, 31 U.S.C. § 3729 et seq. and local statutory counterparts by under reporting Average Manufacturer Price (AMP) information to the Centers for Medicare and Medicaid Services. The United States and the States have declined to intervene. We believe we have good and valid defenses. We have not formed an opinion that an unfavorable outcome under the remaining claims is either “probable” or “remote”.

Government Matters

We have learned that state and federal governmental authorities are investigating our sales and promotional practices and have received related subpoenas. We have also received a subpoena from the federal government for documents relating to our relationship with certain pharmacy benefit managers. We are cooperating with the government in these matters.

Qui Tam Litigation

In August, 2012, we learned that a relator, on behalf of the United States and certain states, filed a suit under seal on February 17, 2011 against us, Elan Corporation, plc, and Elan Pharmaceuticals, Inc. in the United States District Court for the Western District of Virginia. We have neither seen nor been served with the complaint, but understand that it was filed under the Federal False Claims Act.

Product Liability and Other Legal Proceedings

We are also involved in product liability claims and other legal proceedings generally incidental to our normal business activities. While the outcome of any of these proceedings cannot be accurately predicted, we do not believe the ultimate resolution of any of these existing matters would have a material adverse effect on our business or financial condition.