Annual report pursuant to Section 13 and 15(d)

Stock Plans - Additional information (Details)

v3.21.1
Stock Plans - Additional information (Details) - USD ($)
1 Months Ended 12 Months Ended
Jan. 31, 2019
Jul. 31, 2002
Aug. 31, 2001
Dec. 31, 2020
Dec. 31, 2019
Jan. 31, 2021
Dec. 31, 2018
Aug. 31, 2015
Feb. 28, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Weighted-average period for recognizing non-vested stock option       1 year 4 months 24 days          
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number       28,000 40,000        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value       $ 6.30 $ 49.20        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares 4,071                
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit $ 630.00                
Increase In The Price In Respect Of Lower Range In Respect Of Shares Authorised Under Compensation Plan $ 46.50                
Employee Stock Option                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized       $ 5,500,000,000          
Common Stock                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Shares, Outstanding       7,139,000 1,913,000   434,000    
2002 Plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized   7,234              
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number       1,426          
Share Based Compensation Arrangement By Share Based Payment Award Percentage Of Fair Market Value Of Common Stock For Calculating Exercise Price   100.00%              
2001 Non-Qualified Plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized     1,768            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number       412          
Share Based Compensation Arrangement By Share Based Payment Award Percentage Of Fair Market Value Of Common Stock For Calculating Exercise Price     100.00%            
2015 Plan                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized               55,556  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number       30,786          
2015 Plan | Subsequent Events                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized           1,000,000      
2015 Plan | Common Stock                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Shares, Outstanding       24,770          
2014 Plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized                 2,526
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number       1,285          
Stock Compensation Plan                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost         $ 81,000        
Research and development | Stock Compensation Plan                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost         54,000        
Selling, general and administrative | Stock Compensation Plan                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost         $ 27,000