Collaboration and License Agreements (Details)	1 Months Ended			12 Months Ended
	Oct. 31, 2014 USD ($)	Oct. 31, 2014 EUR (€)	Jul. 31, 2005 USD ($)	Dec. 31, 2014 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Ipsen Upfront Payment	$ 23,000,000
Ipsen Revenue Allocated to Development Deliverable	1,600,000
Ipsen Revenue Allocated to Committee Deliverable	100,000
Ipsen Revenue Allocated to License Deliverable	21,200,000
Ipsen Revenue Recognized				21,400,000
Ipsen Maximum Regulatory And Commercial Milestones	30,000,000
Ipsen Maximum Sales Milestones		72,000,000
TX Enterprise Fund Award			35,000,000
TX Enterprise Fund Award to Texas AM University System			15,000,000
TIGM Per Job Payment Amount				2,415
TIGM Maximum Exposure				14,200,000
TIGM Maximum Exposure Through Reporting Date				$ 2,500,000