Annual report pursuant to Section 13 and 15(d)

Note 10 - Equity (Details Textual)

v3.10.0.1
Note 10 - Equity (Details Textual) - USD ($)
1 Months Ended 12 Months Ended
Jun. 01, 2018
Nov. 14, 2014
Sep. 30, 2017
Dec. 31, 2016
Dec. 31, 2013
Dec. 31, 2018
Dec. 31, 2017
May 15, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross           145,792 295,286  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value           $ 3,617,153    
Share Price         $ 0.45      
Stock Repurchased During Period, Shares         534,000      
Stock Repurchased During Period, Value         $ 240,000      
Treasury Stock, Retired, Cost Method, Amount         $ 791,638      
Binomial Lattice-based Model, Fair Value, Share Price         $ 1.03      
Binomial Lattice-based Model, Fair Value, Total         $ 551,638      
Stock Issued During Period, Shares, Treasury Stock Reissued     283,128 250,872        
Stock Issued During Period, Value, Treasury Stock Reissued     $ 292,671 $ 210,000     $ 292,671  
Treasury Stock, Shares, Ending Balance           14,670 14,084  
Treasury Stock, Value, Ending Balance           $ 90,856 $ 86,045  
Class of Warrant Or Right, Issued During Period   90,000            
Class of Warrant or Right, Exercise Price of Warrants or Rights   $ 8.125            
Treasury Stock [Member]                
Stock Issued During Period, Shares, Treasury Stock Reissued             283,128  
Stock Issued During Period, Value, Treasury Stock Reissued     127,000 113,000     $ 419,728  
Common Stock [Member]                
Stock Issued During Period, Value, Treasury Stock Reissued              
Option to Repurchase Shares, Change in Fair Value     (292,000) (259,000)        
Additional Paid-in Capital [Member]                
Stock Issued During Period, Value, Treasury Stock Reissued     $ 127,000 $ 162,000     $ (127,057)  
Employee Stock Option [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross           145,792 295,286  
Allocated Share-based Compensation Expense, Total           $ 363,568 $ 380,067  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options           $ 805,226    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition           2 years 255 days    
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period         8 years      
Restricted Stock [Member]                
Allocated Share-based Compensation Expense, Total           $ 264,862 $ 214,304  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition           2 years 36 days    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options           $ 249,586    
Minimum [Member]                
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Exercise Price           $ 4.92 $ 2.65  
Maximum [Member]                
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Exercise Price           8.25 5.51  
The 2014 Plan [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized               1,513,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized 700,000              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 2,213,000              
The 2014 Plan [Member] | Restricted Stock [Member] | Director [Member]                
Share Price           $ 7.27 $ 4.02  
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost, Total           $ 240,000 $ 240,000  
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted           5,502    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period           1 year    
The 2014 Plan [Member] | Restricted Stock [Member] | Employee [Member]                
Share Price           $ 8.25    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost, Total           $ 141,000    
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted           17,112