Quarterly report pursuant to Section 13 or 15(d)

Stock Plans (Details Textual)

v3.19.1
Stock Plans (Details Textual) - USD ($)
1 Months Ended 3 Months Ended
Jan. 31, 2019
Mar. 31, 2019
Mar. 31, 2018
Aug. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Weighted-average period for recognizing non-vested stock option   3 years 6 months    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares 122,115      
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit $ 21.00      
Increase In The Price In Respect Of Lower Range In Respect Of Shares Authorised Under Comensation Plan $ 1.55      
Research and Development Expense   $ 1,844,000 $ 1,856,000  
Selling, General and Administrative Expense   3,082,000 $ 1,615,000  
Employee Stock Option [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized   62,000    
2015 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 1,666,667     583,334
Stock Compensation Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based Payment Arrangement, Accelerated Cost   81,000    
Research and Development Expense   54,000    
Selling, General and Administrative Expense   $ 27,000