Investments in Variable Interest Entities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Investment in biotechnology companies that are determined to be unconsolidated variable interest entities	$ 39.2	$ 29.2
Neurimmune
Variable Interest Entity [Line Items]
Remaining potential development milestone payments and royalties on commercial sales under the terms of collaboration agreement	$ 275.0
Research and development cost in support of collaboration agreement	100.00%
Other Variable Interest Entities
Variable Interest Entity [Line Items]
Additional investments committed to if certain development milestones are achieved	$ 8.0