Quarterly report pursuant to Section 13 or 15(d)

Stock Plans (Details)

v3.7.0.1
Stock Plans (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock-based compensation expenses $ 382 $ 249 $ 803 $ 581
Research and development [Member]        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock-based compensation expenses 128 85 245 217
General and administrative [Member]        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock-based compensation expenses $ 254 $ 164 $ 558 $ 364