T-Cell Factory Acquisition - Summary of Fair Value of Tangible and Intangible Assets Acquired and Liabilities Assumed (Details) $ in Thousands	Jun. 30, 2015 USD ($)
Business Acquisition Equity Interests Issued Or Issuable [Line Items]
Goodwill	$ 25,798
T-Cell Factory Acquisition
Business Acquisition Equity Interests Issued Or Issuable [Line Items]
Intangible assets	15,400
Goodwill	24,692
Tangible current assets	361
Tangible non-current assets	214
Liabilities assumed	(4,844)
Total purchase price	35,823
T-Cell Factory Acquisition | Non-compete agreements
Business Acquisition Equity Interests Issued Or Issuable [Line Items]
Intangible assets	12,400
T-Cell Factory Acquisition | Licensing agreements
Business Acquisition Equity Interests Issued Or Issuable [Line Items]
Intangible assets	$ 3,000