T-Cell Factory Acquisition - Additional Information (Details) - T-Cell Factory Acquisition € in Millions, $ in Millions			3 Months Ended	6 Months Ended
	Mar. 17, 2015 USD ($) shares	Mar. 17, 2015 EUR (€) shares	Jun. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)
Business Acquisition [Line Items]
Business acquisition, amount paid in cash	$ 15.1
Business acquisition, amount paid in common stock	$ 4.2
Amount withheld from sellers to satisfy potential indemnity claims | €		€ 2.0
Indemnity holdback period	18 months	18 months
Deferred Tax Liabilities			$ 3.8	$ 3.8
Licensing agreements
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life				10 years
Non-compete agreements
Business Acquisition [Line Items]
Reduction in intangible asset			1.1
Reduction in deferred tax liability			0.3
Reduction in contingent consideration liability			1.3
Adjustment as other income			$ 0.5
Maximum
Business Acquisition [Line Items]
Business acquisition, obligations to be paid upon achieving regulatory and sales milestones | €		€ 242.5
Common Stock
Business Acquisition [Line Items]
Business acquisition, number of common stock issued | shares	66,120	66,120