Investments in Variable Interest Entities (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Investment in Variable Interest Entities (Textual) [Abstract]
Research and development	$ 460,549,000	$ 528,884,000
Investment in biotechnology companies that are determined to be unconsolidated variable interest entities	8,500,000		7,900,000
Neurimmune
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
Expected milestone payment for initiation of a late stage clinical trial	60,000,000
Research and development	$ 12,800,000	$ 11,000,000

- 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.

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