Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Stock Option Activity (Details)

v3.19.1
Stock-based Compensation - Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Number of Shares    
Beginning balance - Outstanding (shares) 4,052,913  
Granted (shares) 1,270,500  
Exercised (shares) 0  
Forfeited/Cancelled(shares) (12,915)  
Ending balance - Outstanding (shares) 5,310,498 4,052,913
Exercisable (shares) 2,621,464  
Vested or expected to vest (shares) 5,310,498  
Weighted- Average Exercise Price    
Beginning balance - Outstanding (in dollars per share) $ 4.37  
Granted (in dollars per share) 1.26  
Exercised (in dollars per share) 0  
Forfeited/Cancelled (in dollars per share) 9.35  
Ending balance - Outstanding (in dollars per share) 3.62 $ 4.37
Exercisable (in dollars per share) 5.43  
Vested or expected to vest (in dollars per share) $ 3.62  
Weighted- Average Remaining Contractual Life (in years)    
Balance - Outstanding 7 years 8 months 8 days 7 years 2 months 23 days
Exercisable 6 years 3 months 14 days  
Vested or expected to vest 7 years 8 months 8 days  
Aggregate Intrinsic Value ($000)    
Balance - Outstanding $ 333 $ 0
Exercisable 13  
Vested and expected to vest $ 333