Annual report pursuant to Section 13 and 15(d)

Stock Plans (Details Textual)

v3.8.0.1
Stock Plans (Details Textual) - USD ($)
1 Months Ended 12 Months Ended
May 31, 2009
Oct. 31, 2007
Jul. 31, 2002
Aug. 31, 2001
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Aug. 31, 2016
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 2 months 12 days        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value         $ 1.91 $ 3.10 $ 3.67    
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, Total         $ 710,000        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number         2,100,000 1,700,000      
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     1,300,000            
Share Based Compensation Arrangement By Share Based Payment Award Percentage Of Fair Market Value Of Common Stock For Calculating Exercise Price     100.00%            
Options To Purchase Common Stock         583,758        
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       318,182          
Share Based Compensation Arrangement By Share Based Payment Award Percentage Of Fair Market Value Of Common Stock For Calculating Exercise Price       100.00%          
Options To Purchase Common Stock         193,465        
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               2,500,000  
Share Based Compensation Arrangement by Share Based Payment Award Options Outstanding Number         1,504,000        
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                 454,546
Share Based Compensation Arrangement by Share Based Payment Award Options Outstanding Number         278,925        
Non Qualified Option plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price $ 4.34 $ 13.20              
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period 48 months 48 months              
Award [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross         946,000        
Dr. Rubin [Member] | Non Qualified Option plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross 111,819 79,546              
Mr. Bhonsle [Member] | Non Qualified Option plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross 56,364