Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Stock Option Activity (Details)

v3.20.1
Stock-based Compensation - Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Number of Shares    
Beginning balance - Outstanding (shares) 4,052,913  
Granted (shares) 1,701,500  
Exercised (shares) (22,500)  
Forfeited/expired (shares) (470,053)  
Ending balance - Outstanding (shares) 5,261,860 4,052,913
Exercisable (shares) 2,988,580  
Vested or expected to vest (shares) 5,261,860  
Weighted- Average Exercise Price    
Beginning balance - Outstanding (in dollars per share) $ 4.37  
Granted (in dollars per share) 1.24  
Exercised (in dollars per share) 0.54  
Forfeited/expired (in dollars per share) 7.96  
Ending balance - Outstanding (in dollars per share) 3.06 $ 4.37
Exercisable (in dollars per share) 4.17  
Vested or expected to vest (in dollars per share) $ 3.06  
Weighted- Average Remaining Contractual Life (in years)    
Balance - Outstanding 7 years 7 months 13 days 7 years 2 months 23 days
Exercisable 6 years 9 months 29 days  
Vested or expected to vest 7 years 7 months 13 days  
Aggregate Intrinsic Value ($000)    
Balance - Outstanding $ 0 $ 60
Exercisable   33
Vested and expected to vest   $ 60