Annual report pursuant to Section 13 and 15(d)

Stock Options, Stock Grants and New Stock (Narrative) (Details)

v3.8.0.1
Stock Options, Stock Grants and New Stock (Narrative) (Details)
 12 Months Ended
May 18, 2017
USD ($)
shares
Feb. 08, 2017
$ / shares
shares
May 05, 2016
USD ($)
$ / shares
shares
Feb. 19, 2016
$ / shares
shares
May 12, 2015
USD ($)
shares
Feb. 10, 2015
$ / shares
shares
Jan. 05, 2015
$ / shares
shares
Feb. 20, 2014
Dec. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
USD ($)
$ / shares
shares
Dec. 31, 2015
USD ($)
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Options granted, weighted average fair value (dollars per share) | $ / shares                 $ 6.41 $ 6.24 $ 6.57
Exercised (shares)                 25,632 0 666
Shares of common stock purchased                 0 29,500 100,400
Options exercisable (shares)                 119,861    
Options exercisable, weighted average exercise price (dollars per share) | $ / shares                 $ 12.45    
Share-based compensation expense | $                 $ 638,416 $ 459,473 $ 521,695
Issuance of shares of common stock from the treasury (in shares)                 58,532 62,124 26,118
Issuance of common stock (shares)                 0 0 0
Stock Options [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Exercised (shares)                 25,632   666
Shares of common stock purchased                 20,243    
Cash received from exercise of stock options | $                     $ 8,302
Option exercises, aggregate exercise price | $                 $ 296,050   $ 8,302
Options exercisable (shares)                 119,861 129,762 88,025
Options exercisable, weighted average exercise price (dollars per share) | $ / shares                 $ 12.45 $ 12.12 $ 11.85
Share-based compensation expense | $                 $ 80,966 $ 135,085 $ 278,341
Total unrecognized compensation cost | $                 $ 86,280    
Share-based compensation, weighted average period of recognition (years)                 1 year 10 months 23 days    
2011 Plan [Member] | Stock Options [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Options granted (shares)           32,532          
Options granted, weighted average exercise price (dollars per share) | $ / shares           $ 16.01          
Options granted, weighted average fair value (dollars per share) | $ / shares           $ 6.39          
Risk free interest rate (percent)           2.00%          
Expected volatility rate (percent)           46.00%          
Expected life (years)           7 years          
Expected dividend yield (percent)           2.00%          
2005 Stock Awards Plan [Member] | Stock Options [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Annual vesting rate (percent)               20.00%      
2005 Stock Awards Plan [Member] | Stock Awards [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Share-based compensation expense | $                 $ 557,450 324,388 243,354
Total unrecognized compensation cost | $                 $ 1,073,914    
Share-based compensation, weighted average period of recognition (years)                 2 years 1 month 15 days    
Share-based compensation expense, period of recognition (years)                 60 months    
Share-based compensation expense, net of taxes | $                 $ 354,538 $ 206,311 $ 154,773
Share-based compensation expense, net of taxes, (dollars per share) | $ / shares                 $ 0.04 $ 0.02 $ 0.02
2015 Stock Awards Plan [Member] | Stock Awards [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Annual vesting rate (percent)                 20.00%    
Granted (shares)   44,687 42,193 50,062              
Granted, weighted average grant date fair value (dollars per share) | $ / shares   $ 12.30 $ 8.05 $ 7.51              
Period after grant date, awards vesting begins (years)                 1 year    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized                 250,000    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   3 years 5 years                
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Number of Employees Affected   8 5                
External Consultants [Member] | 2005 Stock Awards Plan [Member] | Stock Awards [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Granted (shares)             3,000        
Granted, weighted average grant date fair value (dollars per share) | $ / shares             $ 17.95        
Non Employee Director [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Issuance of shares of common stock from the treasury (in shares) 24,209   40,991   8,216            
Annual cash retainer fees | $ $ 287,500   $ 330,000   $ 118,750            
Restricted Stock [Member] | Non Employee Director [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Maximum annual retainer percent                 100.00%    
May 5, 2016 [Member] | 2015 Stock Awards Plan [Member] | Stock Awards [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost | $                 $ 75,756    
February 8, 2017 [Member] | 2015 Stock Awards Plan [Member] | Stock Awards [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost | $                 $ 67,180