Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation - Stock Options With Service-based Vesting Conditions (Details)

v3.21.2
Stock Based Compensation - Stock Options With Service-based Vesting Conditions (Details) - Service Based Options - $ / shares
 9 Months Ended 12 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Number of shares    
Balance, beginning of period (in shares) 8,830,674  
Granted (in shares) 5,017,690  
Exercises (in shares) (580,617)  
Forfeited (in shares) (439,341)  
Expired (in shares) (354,994)  
Balance, ending of period (in shares) 12,473,412 8,830,674
Exercisable (in shares) 4,437,524  
Weighted average exercise price per share    
Balance (in dollars per share) $ 3.72 $ 3.95
Granted (in dollars per share) 3.24  
Exercised (in dollars per share) 2.70  
Forfeited (in dollars per share) 3.55  
Expired (in dollars per share) 4.53  
Exercisable (in dollars per share) 4.20  
Option Activity, Fair value of options granted    
Balance (in dollars per share) 2.30 $ 2.36
Granted (in dollars per share) 2.17  
Exercised (in dollars per share) 1.74  
Forfeited (in dollars per share) 2.27  
Expired (in dollars per share) 2.69  
Exercisable (in dollars per share) $ 2.41  
Weighted average remaining contractual term (in years)    
Balance 8 years 4 months 24 days 7 years 8 months 12 days
Exercisable 7 years 4 months 24 days