Annual report pursuant to Section 13 and 15(d)

Note 15 - Share Based Compensation (Details Textual)

v3.19.1
Note 15 - Share Based Compensation (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Payments for Distribution of Restricted Stock, Spin-off   $ 2,700  
Distribution of Restricted Stock in Connection with Spin-off   120,693  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total $ 6,800 $ 5,200  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance $ 14.81    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term 8 years 359 days    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance 805,566 613,700
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term 9 years 8 days    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value $ 0    
Restricted Stock [Member]      
Distribution of Restricted Stock in Connection with Spin-off 120,693  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value $ 12.63    
Restricted Stock, Spin-off [Member]      
Allocated Share-based Compensation Expense, Total   $ 600  
2017 Equity Incentive Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 2,174,000    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 1,157,924    
Allocated Share-based Compensation Expense, Total $ 4,400 $ 800  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance $ 9.99 $ 6.42  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate 0.00% 0.00%  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate 50.40% 52.50%  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Discount for Postvesting Restrictions 2.79% 2.22%  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term 6 years 6 years  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value $ 800    
2017 Equity Incentive Plan [Member] | Restricted Stock [Member]      
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 1 year 165 days    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value $ 21.63 $ 12.50  
2017 Equity Incentive Plan [Member] | Restricted Stock [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period 1 year    
2017 Equity Incentive Plan [Member] | Restricted Stock [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period 4 years    
2017 Equity Incentive Plan [Member] | Employee Stock Option [Member]      
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 1 year 291 days    
2017 Equity Incentive Plan [Member] | Employee Stock Option [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period 1 year    
2017 Equity Incentive Plan [Member] | Employee Stock Option [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period 4 years    
Employee Stock Purchase Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 300,000    
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date   85.00%