Quarterly report pursuant to Section 13 or 15(d)

Note 10 - Stock-based Compensation (Details Textual)

v3.19.2
Note 10 - Stock-based Compensation (Details Textual) - USD ($)
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross     62,944    
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Exercise Price     $ 12.02    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value $ 11,894,226   $ 11,894,226    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value 7,354,410   $ 7,354,410    
Share-based Payment Arrangement, Option [Member]          
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross     62,944   145,792
Share-based Payment Arrangement, Expense 99,846 $ 69,640 $ 196,650 $ 208,813  
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount   920,988   920,988  
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition     2 years 292 days    
Restricted Stock [Member]          
Share-based Payment Arrangement, Expense 79,106 $ 69,347 $ 154,074 $ 137,816  
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition     2 years 73 days    
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount $ 469,307   $ 469,307