Current report filing

Note 8 - Stock-based Compensation (Details Textual)

v3.19.1
Note 8 - Stock-based Compensation (Details Textual) - USD ($)
$ in Thousands
9 Months Ended
Mar. 28, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Subscription Rate   17.50%    
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares   6,120,000    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   4 years    
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period   10 years    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value   $ 230 $ 0  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options   $ 1,740    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition   1 year 244 days    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance   4,471,000   2,344,000
Employee Stock Option Vesting Schedule II [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance   166,000    
Employee Stock Option Vesting Schedule III [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance   850,000    
Restricted Stock Units (RSUs) [Member]        
Stock Redemption, Shares Per Share   1    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period 150,000 150,000 150,000  
Share-based Compensation Award, Tranche One [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   50.00%    
Share-based Compensation Award, Tranche One [Member] | Employee Stock Option Vesting Schedule II [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   50.00%    
Share-based Compensation Award, Tranche Four [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   16.67%    
Share-based Compensation Award, Tranche Two [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   16.67%    
Share-based Compensation Award, Tranche Two [Member] | Employee Stock Option Vesting Schedule II [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   25.00%    
Share-based Compensation Award, Tranche Three [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   16.67%    
Share-based Compensation Award, Tranche Three [Member] | Employee Stock Option Vesting Schedule II [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   25.00%