Investments in Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Investment in biotechnology companies that are determined to be unconsolidated variable interest entities	$ 53.5	$ 47.4
Neurimmune
Variable Interest Entity [Line Items]
Research and development cost in support of collaboration agreement	100.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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