Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Stock-based Compensation (Details Textual)

v3.7.0.1
Note 4 - Stock-based Compensation (Details Textual) - USD ($)
3 Months Ended 6 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Mar. 31, 2016
Dec. 31, 2015
Mar. 31, 2017
Mar. 31, 2016
Allocated Share-based Compensation Expense $ 590,165   $ 246,426   $ 1,183,911 $ 473,193
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized 6,324,696       $ 6,324,696  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition         7 years 219 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross         0 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term         3 years 73 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value 533,632       $ 533,632  
Proceeds from Stock Options Exercised         $ 28,459 $ 84,738
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period         15,750 57,050
Employee Stock Purchase Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Market Price Percentage, Offering Date         85.00%  
Stock Issued During Period, Shares, Employee Stock Purchase Plans   11,144   10,352    
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price   $ 15.21   $ 11.40    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant   131,978        
Restricted Stock [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period         3,795  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value         $ 16.45  
Restricted Stock [Member] | Non Employee Directors [Member] | Stock Compensation Plan 2007 [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period         1 year 1 year
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period         3,795 2,712
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value         $ 16.45 $ 14.73
Restricted Stock [Member] | Outgoing Non Employee Directors [Member] | Stock Compensation Plan 2007 [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period           1,356
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value           $ 14.73
Restricted Stock [Member] | Employees [Member] | Stock Compensation Plan 2007 [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period           5 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period           8,500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value           $ 13.64
Minimum [Member] | Restricted Stock [Member] | Employee and Non-Employee Directors [Member] | Stock Compensation Plan 2007 [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period         1 year  
Maximum [Member] | Restricted Stock [Member] | Employee and Non-Employee Directors [Member] | Stock Compensation Plan 2007 [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period         10 years  
Selling, General and Administrative Expenses [Member]            
Allocated Share-based Compensation Expense 535,464   224,156   $ 1,074,510 $ 429,037
Cost of Sales [Member]            
Allocated Share-based Compensation Expense $ 54,701   $ 22,270   $ 109,401 $ 44,156