Annual report pursuant to Section 13 and 15(d)

Note 9 - Summary of Stock Options (Details Textual)

v3.6.0.2
Note 9 - Summary of Stock Options (Details Textual) - USD ($)
1 Months Ended 12 Months Ended
Dec. 23, 2016
Aug. 22, 2016
Nov. 30, 2016
Sep. 30, 2016
Aug. 31, 2016
Jan. 31, 2016
Dec. 31, 2016
Dec. 31, 2015
Aug. 21, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number             1,909,764 1,022,195  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price             $ 6.19 $ 6.47  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term             9 years 43 days 9 years 135 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross             978,966    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period             3,020    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options             $ 3,757,000    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition             3 years 98 days    
Employees [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate             0.00% 0.00%  
Nonemployees [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate             0.00%    
Employee Stock Option [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate             0.00%    
Two Thousand Five Plan [Member]                  
Common Stock, Capital Shares Reserved for Future Issuance             1,892    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number             1,892    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price             $ 116.29    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term             266 days    
The 2006 Stock Option Plan [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number             38,378    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price             $ 10.49    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term             5 years 321 days    
Conversion of Stock Exchange Ratio             0.0080497    
Conversion of Stock, Post Revenue Stock Split Basis, Ratio             0.0010062    
The 2013 Plan [Member]                  
Common Stock, Capital Shares Reserved for Future Issuance             10,236    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number             1,869,494    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price             $ 5.99    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term             9 years 69 days    
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period             10 years    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period             4 years    
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum             10.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent             110.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Period Increase (Decrease)   737,500              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized   2,000,000             1,262,500
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Percentage Increase of Outstanding Common Stock 4.00% 4.00%              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized 523,209                
The 2013 Plan [Member] | Employees [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross             919,841 753,880  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value             $ 2.63 $ 3.13  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value             $ 5,000    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period               0  
The 2013 Plan [Member] | Nonemployees [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross             59,125 0  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value             $ 4.60    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period             0 0  
The 2013 Plan [Member] | Restricted Stock [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number             58,155    
The 2013 Plan [Member] | Restricted Stock [Member] | Employees [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period           39,494      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value           $ 6.24      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period             0    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period       89          
The 2013 Plan [Member] | Restricted Stock [Member] | Board Members [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period     6,544   5,998        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value     $ 5.91   $ 7.89        
The 2013 Plan [Member] | Restricted Stock [Member] | Consultant [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period       1 year          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period       25,000          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value       $ 7.58          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period             6,250    
The 2013 Plan [Member] | Holdings Greater Than 10 Percent of Shares Outstanding [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period             5 years    
The 2013 Plan [Member] | Quarterly [Member] | Restricted Stock [Member] | Consultant [Member]                  
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage       25.00%