Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation (Details Textual)

v3.5.0.2
Stock-based Compensation (Details Textual) - USD ($)
shares in Thousands, $ in Thousands
6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation, Total $ 2,101 $ 791
Research and Development Expense [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation, Total 59  
General and Administrative Expense [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation, Total 774  
Employee Stock Option [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options $ 5,560  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 2 years 9 months 18 days  
Equity Incentive Plan 2014 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 3,714  
Common Stock, Capital Shares Reserved for Future Issuance 1,149