Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Details Textual)

v3.8.0.1
Stock-Based Compensation (Details Textual) - USD ($)
1 Months Ended 3 Months Ended
Mar. 20, 2007
Mar. 31, 2018
Mar. 31, 2017
Sep. 07, 2017
Aug. 25, 2016
May 15, 2015
Oct. 22, 2013
Nov. 02, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options   $ 2,100,000            
Employees And Consultants [Member] | General and Administrative Expenses and Research and Development Expense [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Allocated Share-based Compensation Expense   $ 700,000 $ 1,100,000          
Employee [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     543,927          
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value     $ 308,000          
2007 Stock Plan [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number 2,500,000 712,258            
2007 Stock Plan [Member] | Maximum [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 250,000              
2010 Stock Plan [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number   11,476,257           3,000,000
2010 Stock Plan [Member] | Maximum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Common Stock, Capital Shares Reserved for Future Issuance       17,500,000 14,000,000 8,000,000 6,000,000  
2010 Stock Plan [Member] | Minimum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Common Stock, Capital Shares Reserved for Future Issuance         8,000,000 6,000,000 3,000,000