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Investments in Variable Interest Entities (Details) (USD $) | 3 Months Ended | 9 Months Ended |  | 3 Months Ended | 9 Months Ended | 1 Months Ended |  | 1 Months Ended
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Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 | Sep. 30, 2014 Neurimmune | Jun. 30, 2014 Neurimmune | Sep. 30, 2013 Neurimmune | Sep. 30, 2014 Neurimmune | Sep. 30, 2013 Neurimmune | Feb. 28, 2014 Ataxion | Feb. 28, 2014 Commitments to invest Ataxion | Feb. 28, 2014 Minority interest Ataxion
Investment in Variable Interest Entities (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration agreement |  |  |  |  |  |  |  |  | $ 335,000,000 |  |  |  |
Research and development | 417,174,000 | 410,017,000 | 1,393,331,000 | 1,021,820,000 |  | 7,400,000 |  | 6,100,000 | 29,100,000 | 16,800,000 |  |  |
Milestone payments made during period |  |  |  |  |  |  | 10,000,000 |  |  |  |  |  |
Payments to acquire interest in preferred stock of affiliate |  |  |  |  |  |  |  |  |  |  | 1,600,000 |  |
Term for right to purchase outstanding shares |  |  |  |  |  |  |  |  |  |  | 30 days |  |
Additional investments committed to if certain milestones are met |  |  |  |  |  |  |  |  |  |  |  | 6,200,000 |
In-process research and development |  |  |  |  |  |  |  |  |  |  |  |  | 3,500,000
Investment in biotechnology companies that are determined to be unconsolidated variable interest entities | $ 6,400,000 |  | $ 6,400,000 |  | $ 5,500,000 |  |  |  |  |  |  |  |

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- Definition Investment in biotechnology companies that are determined to be unconsolidated variable interest entities. + References No definition available. + Details
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- Details
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- Definition Milestone Payments Made During Period. + References No definition available. + Details
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- Definition Expected total payments including upfront and milestone payments as well as the greater of an annual maintenance fee or usage-based royalty payments under the terms of collaboration agreement. + References No definition available. + Details
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- Definition Term For Right To Purchase Outstanding Shares + References No definition available. + Details
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- Definition Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions. + References No definition available. + Details
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- Definition The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585 + Details
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- Definition The costs incurred 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 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, excluding in-process research and development acquired in a business combination consummated during the period. Excludes software research and development, which has a separate concept. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 730 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Research and Development -URI http://asc.fasb.org/extlink&oid=6523717 + Details
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