XML 53 R42.htm IDEA: XBRL DOCUMENT v3.19.1
Stockholders’ Equity - Schedule of Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Stock Options    
Granted (in shares) 822,975  
Weighted Average Contractual Term    
Contractual term 10 years  
Common stock options    
Stock Options    
Beginning balance (in shares) 3,257,801  
Granted (in shares) 822,975  
Exercised (in shares) (20,544)  
Cancelled/forfeited (in shares) (192,978)  
Ending balance (in shares) 3,867,254 3,257,801
Exercisable (in shares) 438,023  
Weighted Average Exercise Price    
Beginning balance (in dollars per share) $ 11.99  
Granted (in dollars per share) 18.09  
Exercised (in dollars per share) 9.98  
Cancelled/forfeited (in dollars per share) 12.15  
Ending balance (in dollars per share) 13.29 $ 11.99
Exercisable (in dollars per share) $ 10.15  
Weighted Average Contractual Term    
Contractual term 8 years 285 days 9 years 3 months 4 days
Exercisable 4 years 310 days  
Aggregate Intrinsic Value    
Beginning balance $ 7,119  
Granted  
Exercised  
Cancelled/forfeited  
Ending balance 37,345 $ 7,119
Exercisable $ 5,440