Investments in Variable Interest Entities	9 Months Ended
Sep. 30, 2012
Investments in Variable Interest Entities [Abstract]
Investments in Variable Interest Entities	Investments in Variable Interest Entities Consolidated Variable Interest Entities Our condensed consolidated financial statements include the financial results of variable interest entities in which we are the primary beneficiary. Knopp In 2010, we purchased 30.0% of the Class B common shares of Knopp Neurosciences, Inc. (Knopp), a subsidiary of Knopp Holdings, LLC, and entered into a license agreement with Knopp for the development, manufacture and commercialization of dexpramipexole, an orally administered small molecule in clinical development for the treatment of amyotrophic lateral sclerosis (ALS). We are responsible for all development activities and, if successful, we will also be responsible for the manufacture and global commercialization of dexpramipexole. Based on our current development plans, we may pay Knopp up to an additional $255.0 million in remaining development and sales-based milestone payments, as well as royalties on future commercial sales. We determined that we are the primary beneficiary of Knopp because we have the power through the license agreement to direct the activities that most significantly impact Knopp’s economic performance and are required to fund 100% of the research and development costs incurred in support of the collaboration agreement. As such, we consolidate the results of Knopp. We are responsible for the development of dexpramipexole and reimburse certain Knopp expenses directly attributable to the license agreement. Amounts incurred by Knopp that we reimburse are reflected as research and development expenses in our condensed consolidated statements of income. Future development and sales-based milestone payments also will be reflected within our condensed consolidated statements of income as a charge to noncontrolling interests, net of tax, when such milestones are achieved. For the three and nine months ended September 30, 2012, the collaboration incurred development expense totaling $15.7 million and $58.9 million, respectively, which is reflected as research and development expense within our condensed consolidated statements of income, compared to $21.8 million and $36.5 million, respectively, in the prior year comparative periods. During the first quarter of 2011, we dosed the first patient in a registrational study for dexpramipexole. The achievement of this milestone resulted in a $10.0 million milestone due to Knopp, which was reflected as a charge to noncontrolling interests. The assets and liabilities of Knopp are not significant to our financial position or results of operations. We have provided no financing to Knopp other than contractually required amounts disclosed above. Neurimmune SubOne AG In 2007, we entered into a collaboration agreement with Neurimmune SubOne AG (Neurimmune), a subsidiary of Neurimmune AG, for the development and commercialization of antibodies for the treatment of Alzheimer’s disease. Neurimmune conducts research to identify potential therapeutic antibodies and we are responsible for the development, manufacturing and commercialization of all products. Based upon our current development plans, we may pay Neurimmune up to $345.0 million in remaining milestone payments, as well as royalties on sales of any resulting commercial products. We determined that we are the primary beneficiary of Neurimmune because we have the power through the collaboration agreement to direct the activities that most significantly impact the entity’s economic performance and are required to fund 100% of the research and development costs incurred in support of the collaboration agreement. As such, we consolidate the results of Neurimmune. Research and development expenses incurred by Neurimmune in support of the collaboration that we reimburse are reflected in research and development expense in our condensed consolidated statements of income. Future milestone payments will be reflected within our condensed consolidated statements of income as a charge to the noncontrolling interest, net of tax, when such milestones are achieved. For the three and nine months ended September 30, 2012, the collaboration incurred development expense totaling $3.4 million and $8.5 million, respectively, which is reflected as research and development expense within our condensed consolidated statements of income, compared to $1.5 million and $6.3 million, respectively, in the prior year comparative periods. In April 2011, we submitted an Investigational New Drug (IND) application for BIIB37 (human anti-Amyloid B mAb), a beta-amyloid removal therapy. The achievement of this milestone resulted in a $15.0 million milestone due to Neurimmune, which was reflected as a charge to noncontrolling interests in the second quarter of 2011. The assets and liabilities of Neurimmune are not significant to our financial position or results of operations as it is a research and development organization. We have provided no financing to Neurimmune other than previously contractually required amounts disclosed above. Unconsolidated Variable Interest Entities We have relationships with other variable interest entities which we do not consolidate as we lack the power to direct the activities that significantly impact the economic success of these entities. These relationships include investments in certain biotechnology companies and research collaboration agreements. For additional information related to our significant collaboration arrangements with unconsolidated variable interest entities, please read Note 20, Collaborations to our consolidated financial statements included within our 2011 Form 10-K. As of September 30, 2012 and December 31, 2011, the total carrying value of our investments in biotechnology companies that we have determined to be variable interest entities, but do not consolidate as we do not have the power to direct their activities, totaled $9.3 million and $14.6 million, respectively. Our maximum exposure to loss related to these variable interest entities is limited to the carrying value of our investments. We have provided no financing to these variable interest entities other than previously contractually required amounts. For additional information related to our investments in variable interest entities, please read Note 19, Investments in Variable Interest Entities to our consolidated financial statements included within our 2011 Form 10-K.

Investments in Variable Interest Entities

Consolidated Variable Interest Entities

Our condensed consolidated financial statements include the financial results of variable interest entities in which we are the primary beneficiary.

Knopp

In 2010, we purchased 30.0% of the Class B common shares of Knopp Neurosciences, Inc. (Knopp), a subsidiary of Knopp Holdings, LLC, and entered into a license agreement with Knopp for the development, manufacture and commercialization of dexpramipexole, an orally administered small molecule in clinical development for the treatment of amyotrophic lateral sclerosis (ALS). We are responsible for all development activities and, if successful, we will also be responsible for the manufacture and global commercialization of dexpramipexole. Based on our current development plans, we may pay Knopp up to an additional $255.0 million in remaining development and sales-based milestone payments, as well as royalties on future commercial sales. We determined that we are the primary beneficiary of Knopp because we have the power through the license agreement to direct the activities that most significantly impact Knopp’s economic performance and are required to fund 100% of the research and development costs incurred in support of the collaboration agreement. As such, we consolidate the results of Knopp.

We are responsible for the development of dexpramipexole and reimburse certain Knopp expenses directly attributable to the license agreement. Amounts incurred by Knopp that we reimburse are reflected as research and development expenses in our condensed consolidated statements of income. Future development and sales-based milestone payments also will be reflected within our condensed consolidated statements of income as a charge to noncontrolling interests, net of tax, when such milestones are achieved.

For the three and nine months ended September 30, 2012, the collaboration incurred development expense totaling $15.7 million and $58.9 million, respectively, which is reflected as research and development expense within our condensed consolidated statements of income, compared to $21.8 million and $36.5 million, respectively, in the prior year comparative periods. During the first quarter of 2011, we dosed the first patient in a registrational study for dexpramipexole. The achievement of this milestone resulted in a $10.0 million milestone due to Knopp, which was reflected as a charge to noncontrolling interests.

The assets and liabilities of Knopp are not significant to our financial position or results of operations. We have provided no financing to Knopp other than contractually required amounts disclosed above.

Neurimmune SubOne AG

In 2007, we entered into a collaboration agreement with Neurimmune SubOne AG (Neurimmune), a subsidiary of Neurimmune AG, for the development and commercialization of antibodies for the treatment of Alzheimer’s disease. Neurimmune conducts research to identify potential therapeutic antibodies and we are responsible for the development, manufacturing and commercialization of all products. Based upon our current development plans, we may pay Neurimmune up to $345.0 million in remaining milestone payments, as well as royalties on sales of any resulting commercial products. We determined that we are the primary beneficiary of Neurimmune because we have the power through the collaboration agreement to direct the activities that most significantly impact the entity’s economic performance and are required to fund 100% of the research and development costs incurred in support of the collaboration agreement. As such, we consolidate the results of Neurimmune.

Research and development expenses incurred by Neurimmune in support of the collaboration that we reimburse are reflected in research and development expense in our condensed consolidated statements of income. Future milestone payments will be reflected within our condensed consolidated statements of income as a charge to the noncontrolling interest, net of tax, when such milestones are achieved.

For the three and nine months ended September 30, 2012, the collaboration incurred development expense totaling $3.4 million and $8.5 million, respectively, which is reflected as research and development expense within our condensed consolidated statements of income, compared to $1.5 million and $6.3 million, respectively, in the prior year comparative periods. In April 2011, we submitted an Investigational New Drug (IND) application for BIIB37 (human anti-Amyloid B mAb), a beta-amyloid removal therapy. The achievement of this milestone resulted in a $15.0 million milestone due to Neurimmune, which was reflected as a charge to noncontrolling interests in the second quarter of 2011.

The assets and liabilities of Neurimmune are not significant to our financial position or results of operations as it is a research and development organization. We have provided no financing to Neurimmune other than previously contractually required amounts disclosed above.

Unconsolidated Variable Interest Entities

We have relationships with other variable interest entities which we do not consolidate as we lack the power to direct the activities that significantly impact the economic success of these entities. These relationships include investments in certain biotechnology companies and research collaboration agreements. For additional information related to our significant collaboration arrangements with unconsolidated variable interest entities, please read Note 20, Collaborations to our consolidated financial statements included within our 2011 Form 10-K.

As of September 30, 2012 and December 31, 2011, the total carrying value of our investments in biotechnology companies that we have determined to be variable interest entities, but do not consolidate as we do not have the power to direct their activities, totaled $9.3 million and $14.6 million, respectively. Our maximum exposure to loss related to these variable interest entities is limited to the carrying value of our investments.

We have provided no financing to these variable interest entities other than previously contractually required amounts.

For additional information related to our investments in variable interest entities, please read Note 19, Investments in Variable Interest Entities to our consolidated financial statements included within our 2011 Form 10-K.