Registration of securities issued in business combination transactions

The following table summarizes changes in the number of outstanding stock options (Details)

v3.21.4
The following table summarizes changes in the number of outstanding stock options (Details) - $ / shares
9 Months Ended 12 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Payment Arrangement [Abstract]        
Options, Outstanding - Beginning 1,173,190 1,130,472 1,380,492  
Weighted average exercise price per share, Outstanding - Beginning $ 6.52 $ 7.28 $ 7.56  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term 3 years 1 month 20 days 3 years 4 months 6 days 3 years 5 months 23 days 4 years 2 months 5 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross 191,301 100,769  
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price $ 5.10 $ 2.69  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (799,390) (8,000) (151,950)  
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price $ 4.70 $ 2.64 $ 4.08  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period (373,800) (140,583) (198,839)  
Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price $ 10.43 $ 10.90 $ 9.33  
Options, Outstanding - Ending 1,173,190 1,130,472 1,380,492
Weighted average exercise price per share, Outstanding - Ending $ 6.52 $ 7.28 $ 7.56
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number 877,926    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price $ 7.20    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term 2 years 8 months 19 days 2 years 7 months 2 days    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number 1,173,190    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price $ 6.52    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term 3 years 1 month 20 days 3 years 4 months 6 days