Quarterly report pursuant to Section 13 or 15(d)

Stock Plans (Details 2)

v3.8.0.1
Stock Plans (Details 2) - Employee Stock Option [Member] - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Options, Outstanding 2,728  
Options, Granted 945  
Options, Exercised 0  
Options, Expired or cancelled 0  
Options, Forfeited 0  
Options, Outstanding 3,673 2,728
Options, Exercisable at March 31, 2018 2,416  
Weighted Average Exercise Price, Outstanding at Beginning of Period $ 4.32  
Weighted Average Exercise Price, Granted 0.97  
Weighted Average Exercise Price, Exercised 0  
Weighted Average Exercise Price, Expired or cancelled 0  
Weighted Average Exercise Price, Forfeited 0  
Weighted Average Exercise Price, Outstanding at End of Period 3.46 $ 4.32
Weighted Average Exercise Price, Exercisable at March 31, 2018 $ 4.48  
Weighted Average Remaining Option Term, Outstanding (Years) 6 years 7 months 20 days 5 years 9 months
Weighted Average Remaining Option Term, Exercisable at March 31, 2018 5 years 8 months 1 day  
Aggregate Intrinsic Value, Outstanding $ 76 $ 30
Aggregate Intrinsic Value, Exercisable at March 31, 2018 $ 19