Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Summary of Stock Option Activity (Details)

v3.19.2
Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]    
Options Outstanding at January 1, 2019 1,320,197  
Options exercised (54,720)  
Options forfeited (3,531)  
Options cancelled 0  
Options Outstanding at March 31, 2019 1,261,946 1,320,197
Outstanding at January, 1, 2019, Weighted average exercise price per share $ 0.77  
Options exercised, Weighted average exercise price per share 0.75  
Options forfeited, Weighted average exercise price per share 0.92  
Outstanding at March 31, 2019, Weighted average exercise price per share $ 0.77 $ 0.77
Outstanding, Weighted average remaining contractual life (in years) 7 years 9 months 7 years 11 months 26 days
Outstanding, Aggregate Intrinsic Value $ 12,836 $ 8,465
Options Vested and expected to vest 1,261,946  
Options Vested 767,573  
Vested and expected to vest, Weighted average exercise price per share $ 0.77  
Vested, Weighted average exercise price per share $ 0.75  
Vested and expected to vest, Weighted average remaining contractual life (in years) 7 years 9 months  
Vested, Weighted average remaining contractual life (in years) 6 years 11 months 19 days  
Vested and expected to vest, Aggregate Intrinsic Value $ 12,836  
Vested, Aggregate Intrinsic Value $ 7,820