License Agreements and Grants - Arizona Commerce Authority and R&D Refundable Tax Credit Program (Details)	1 Months Ended	12 Months Ended
	Aug. 31, 2012 USD ($) job milestone	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Research and Development [Abstract]
Arizona Commerce Authority grant | $	$ 1,000,000	$ 1,000,000	$ 1,000,000
Number of milestones | milestone	4
Qualified jobs created, milestone 1 | job	15
Qualified jobs created, milestone 2 | job	30
Qualified jobs created, milestone 3 | job	40
Qualified jobs created, milestone 4 | job	65
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Offset to research and development project | $		$ 1,200,000	$ 647,000	$ 527,000
Minimum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Capital investment milestone | $	$ 4,500,000
Grant related minimum annual wages | $	$ 63,000
Percent of company paid premiums	65.00%