XML 59 R43.htm IDEA: XBRL DOCUMENT v3.19.1
Note 9 - Stock-based Compensation (Details Textual) - USD ($)
12 Months Ended
Jan. 01, 2018
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term   5 years 255 days      
Allocated Share-based Compensation Expense, Total   $ 3,429,000 $ 3,227,000 $ 3,343,000  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross   2,041,600 719,337 132,495  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value   $ 2.61 $ 1.99 $ 5.08  
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price   $ 2.61   $ 7.11  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value   $ 0 $ 27,000    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options   $ 4,600,000 $ 4,200,000    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition   2 years 146 days 2 years 146 days    
Common Stock, Capital Shares Reserved for Future Issuance   27,394,852 25,877,695    
Employee Stock Option [Member] | Non-Employees [Member]          
Allocated Share-based Compensation Expense, Total   $ 0 $ 0 $ 0  
The 2014 Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized   704,000      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Annual Additional Shares, Percentage   4.00%      
The 2014 Plan [Member] | Minimum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   3 years      
The 2014 Plan [Member] | Maximum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   4 years      
The 2006 Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term   10 years      
The 2014 Employee Stock Purchase Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized   304,991      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Annual Additional Shares, Percentage   1.00%      
Allocated Share-based Compensation Expense, Total   $ 100,000 $ 100,000 $ 100,000  
Common Stock, Capital Shares Reserved for Future Issuance   118,120 192,463   140,500
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Additional Shares Authorizable 281,000        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized 0        
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period   74,343 100,358