Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Stock-based Compensation Expense (Details)

v3.20.2
Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended
Aug. 31, 2020
Jun. 30, 2020
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Schedule of stock-based compensation expense            
Stock-based compensation     $ 1,984 $ 1,732 $ 6,092 $ 5,783
Nonemployee [Member]            
Schedule of stock-based compensation expense            
Number of options granted (shares) 16,000 60,000        
Fair value of options granted $ 100 $ 300        
Stock Options [Member]            
Schedule of stock-based compensation expense            
Stock-based compensation     619 545 $ 1,735 1,680
Award vesting period         4 years  
Compensation not yet recognized, stock options     4,200   $ 4,200  
Stock Options [Member] | Tranche One [Member]            
Schedule of stock-based compensation expense            
Award vesting rights (percent)         25.00%  
Stock Options [Member] | Tranche Two [Member]            
Schedule of stock-based compensation expense            
Award vesting rights (percent)         75.00%  
RSUs and RSAs [Member]            
Schedule of stock-based compensation expense            
Stock-based compensation     603 461 $ 1,812 1,308
Compensation not yet recognized, share-based awards other than options     2,300   2,300  
PSUs [Member]            
Schedule of stock-based compensation expense            
Stock-based compensation     295 368 922 1,075
Compensation not yet recognized, share-based awards other than options     800   800  
PBOs [Member]            
Schedule of stock-based compensation expense            
Stock-based compensation     467 358 1,623 1,720
Compensation not yet recognized, share-based awards other than options     1,300   1,300  
Non-Employee Stock Options [Member]            
Schedule of stock-based compensation expense            
Compensation not yet recognized, stock options     300   300  
Non-Employee Stock Options [Member] | Nonemployee [Member]            
Schedule of stock-based compensation expense            
Expected volatility rate 50.50% 51.90%        
Risk free interest rate 0.30% 0.40%        
Expected dividend yield 0.00% 0.00%        
Award vesting period 1 year 2 years        
Stock-based compensation expense     43   47  
Non-Employee Stock Options [Member] | Nonemployee [Member] | Tranche One [Member]            
Schedule of stock-based compensation expense            
Award vesting rights (percent)   50.00%        
Non-Employee Stock Options [Member] | Nonemployee [Member] | Tranche Two [Member]            
Schedule of stock-based compensation expense            
Award vesting rights (percent) 100.00% 50.00%        
Research and Development [Member]            
Schedule of stock-based compensation expense            
Stock-based compensation     385 458 1,279 1,249
Selling, General and Administrative [Member]            
Schedule of stock-based compensation expense            
Stock-based compensation     $ 1,599 $ 1,274 $ 4,813 $ 4,534