v3.23.2
Stockholders' Equity - Stock Option Activity (Details) - USD ($)
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Shares      
Exercised (in shares)   0  
Aggregate Intrinsic Value      
Exercised, aggregate intrinsic value $ 0 $ 0 $ 400,000
Stock options      
Shares      
Outstanding beginning balance (in shares) 11,398,215    
Granted (in shares) 3,809,200    
Exercised (in shares) (142,440)    
Forfeited (in shares) (3,331,840)    
Expired/cancelled (in shares) (407,045)    
Outstanding ending balance (in shares) 11,326,090 11,398,215  
Options exercisable at end of period (in shares) 6,239,437    
Vested and expected to vest at end of period (in shares) 11,326,090    
Weighted-Average Exercise Price      
Outstanding beginning balance, weighted-average exercise price (in dollars per share) $ 7.60    
Granted, weighted-average exercise price (in dollars per share) 1.81    
Exercised, weighted-average exercise price (in dollars per share) 0.47    
Forfeited, weighted-average exercise price (in dollars per share) 6.43    
Expired/cancelled, weighted-average exercise price (in dollars per share) 9.52    
Outstanding ending balance, weighted-average exercise price (in dollars per share) 6.01 $ 7.60  
Options exercisable at end of period, weighted-average exercise price (in dollars per share) 8.37    
Vested and expected to vest at end of period, weighted-average exercise price ( in dollars per share) $ 6.01    
Weighted-Average Contractual Life (in years)      
Outstanding balance, weighted-average contractual life (in years) 7 years 3 months 3 days    
Options exercisable at end of period, weighted-average contractual life (in years) 6 years 29 days    
Aggregate Intrinsic Value      
Outstanding beginning balance, aggregate intrinsic value $ 267,830    
Exercised, aggregate intrinsic value 44,905    
Forfeited, aggregate intrinsic value 3,813    
Outstanding ending balance, aggregate intrinsic value 112,709 $ 267,830  
Options exercisable at end of period, aggregate intrinsic value $ 1,904