Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Options (Details)

v3.19.2
Stock-Based Compensation - Options (Details)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
USD ($)
shares
Jun. 30, 2018
USD ($)
Jun. 30, 2019
USD ($)
item
$ / shares
shares
Jun. 30, 2018
USD ($)
Stock Based Compensation        
Share-based compensation | $ $ 2,653 $ 1,112 $ 5,606 $ 2,652
Additional disclosures        
Shares of common stock available for grant 10,560,702   10,560,702  
Employee stock option        
Stock Based Compensation        
Number of homogenous groups for purposes of determining fair values of options | item     3  
Contractual term of the option     10 years  
Weighted-average assumptions relating to options granted        
Risk-free interest rate (as a percent) 2.20% 2.90% 2.50% 2.70%
Expected term (in years) 6 years 8 months 12 days 6 years 7 months 6 days 6 years 7 months 6 days 6 years 8 months 12 days
Dividend yield (as a percent) 0.00% 0.00% 0.00% 0.00%
Expected volatility (as a percent) 65.00% 66.20% 65.80% 65.00%
Additional disclosures        
Options granted (in shares)     6,301,275  
Grant-date weighted-average fair value (in dollars per share) | $ / shares     $ 1.27  
Options exercised during the period (in shares)     30,272  
Employee stock option | Vesting upon achievement of corporate performance-based milestones        
Additional disclosures        
Options outstanding 1,012,500   1,012,500  
Total unrecognized compensation costs | $ $ 1,400   $ 1,400  
Employee stock option | Consultant        
Stock Based Compensation        
Contractual term of the option     10 years  
Employee stock option | Recipient of performance shares        
Additional disclosures        
Total unrecognized compensation costs | $ $ 12,400   $ 12,400