XML 24 R39.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock-Based Compensation Plan - Additional Information (Details) - USD ($)
12 Months Ended
Dec. 21, 2017
Dec. 31, 2019
Dec. 31, 2018
Dec. 19, 2019
Stock Based Compensation Plans [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross   35,000 20,000  
Common Stock Shares Available For Future Issuance Value   $ 609,121    
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period   10 years    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value   $ 16.26 $ 26.55  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options   $ 600,000    
Stock-based compensation expense   $ 700,000 $ 600,000  
Share-based Compensation Arrangement By Share-based Payment Award, Options Outstanding And Unvested, Weighted Average Remaining Contractual Term   2 years 2 months 12 days    
Stock Incentive Plan 2007 [Member]        
Stock Based Compensation Plans [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross 0      
Incremental number of shares reserved for grant and issuance       600,000
Stock Incentive Plan 2007 [Member] | Maximum [Member]        
Stock Based Compensation Plans [Line Items]        
Incremental number of shares reserved for grant and issuance       660,000
Research and Development Expense [Member]        
Stock Based Compensation Plans [Line Items]        
Stock-based compensation expense   $ 100,000 100,000  
General and Administrative Expense [Member]        
Stock Based Compensation Plans [Line Items]        
Stock-based compensation expense   $ 600,000 $ 500,000