Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Summary of Stock Option Information by Exercise Price Range (Details)

v3.20.1
Stock-Based Compensation - Summary of Stock Option Information by Exercise Price Range (Details)
12 Months Ended
Dec. 31, 2019
$ / shares
shares
Number of options outstanding | shares 4,078,000
Options outstanding, weighted - average remaining contractual life in years 8 years
Options outstanding, weighted - average exercise price $ 5.79
Number of options exercisable | shares 847,000
Options exercisable, weighted - average exercise price $ 5.71
Exercise Price Range One [Member]  
Exercise price, upper limit 2.06
Exercise price, lower limit $ 4.87
Number of options outstanding | shares 393,000
Options outstanding, weighted - average remaining contractual life in years 5 years
Options outstanding, weighted - average exercise price $ 4.20
Number of options exercisable | shares 242,000
Options exercisable, weighted - average exercise price $ 4.10
Exercise Price Range Two [Member]  
Exercise price, upper limit 4.88
Exercise price, lower limit $ 5.70
Number of options outstanding | shares 235,000
Options outstanding, weighted - average remaining contractual life in years 5 years
Options outstanding, weighted - average exercise price $ 5.37
Number of options exercisable | shares 199,000
Options exercisable, weighted - average exercise price $ 5.41
Exercise Price Range Three [Member]  
Exercise price, upper limit 5.71
Exercise price, lower limit $ 5.97
Number of options outstanding | shares 1,652,000
Options outstanding, weighted - average remaining contractual life in years 9 years
Options outstanding, weighted - average exercise price $ 5.86
Number of options exercisable | shares 213,000
Options exercisable, weighted - average exercise price $ 5.81
Exercise Price Range Four [Member]  
Exercise price, upper limit 5.98
Exercise price, lower limit $ 6.90
Number of options outstanding | shares 1,798,000
Options outstanding, weighted - average remaining contractual life in years 9 years
Options outstanding, weighted - average exercise price $ 6.11
Number of options exercisable | shares 193,000
Options exercisable, weighted - average exercise price $ 6.06