Annual report pursuant to Section 13 and 15(d)

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

v3.6.0.2
Stock Options, Stock Grants and New Stock (Narrative) (Details) - USD ($)
 12 Months Ended
May 05, 2016
Feb. 19, 2016
May 12, 2015
Feb. 10, 2015
Jan. 05, 2015
Nov. 21, 2014
Oct. 16, 2014
Apr. 24, 2014
Feb. 20, 2014
Dec. 31, 2016
Dec. 31, 2015
Jan. 03, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Options granted, weighted average fair value (dollars per share)                   $ 6.24 $ 6.57 $ 6.76
Exercised (shares)                   0 666 17,074
Shares of common stock purchased                   29,500 100,400 0
Options exercisable (shares)                   129,762    
Options exercisable, weighted average exercise price (dollars per share)                   $ 12.12    
Share-based compensation expense                   $ 459,473 $ 521,695 $ 364,157
Issuance of shares of common stock from the treasury (in shares)                   62,124 26,118 14,522
Issuance of common stock (shares)                   0 0 0
Stock Options [Member]                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Exercised (shares)                   0 666 17,074
Option exercises, aggregate exercise price                     $ 8,000 $ 192,000
Cash received from exercise of stock options                     $ 8,000 $ 42,000
Shares of common stock purchased                       9,094
Stock repurchased during year                       $ 150,000
Options exercisable (shares)                   129,762 88,025 56,787
Options exercisable, weighted average exercise price (dollars per share)                   $ 12.12 $ 11.85 $ 11.73
Share-based compensation expense                   $ 135,000 $ 278,000 $ 261,000
Total unrecognized compensation cost                   $ 173,000    
Share-based compensation, weighted average period of recognition (years)                   2 years 6 months    
2011 Plan [Member] | Stock Options [Member]                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Options granted (shares)       32,532         13,790      
Options granted, weighted average exercise price (dollars per share)       $ 16.01         $ 14.76      
Options granted, weighted average fair value (dollars per share)       $ 6.39         $ 6.70      
Risk free interest rate (percent)       2.00%         2.00%      
Expected volatility rate (percent)       46.00%         52.00%      
Expected life (years)       7 years         7 years      
Expected dividend yield (percent)       2.00%         1.80%      
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                   $ 324,000 $ 243,000 103,000
Total unrecognized compensation cost                   $ 1,082,000    
Share-based compensation, weighted average period of recognition (years)                     3 years 6 months 28 days  
Share-based compensation expense, period of recognition (years)                   60 months    
Share-based compensation expense, net of taxes                   $ 207,000 $ 155,000 $ 66,000
Share-based compensation expense, net of taxes, (dollars per share)                   $ 0.02 $ 0.02 $ 0.01
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) 42,348 50,062                    
Granted, weighted average grant date fair value (dollars per share) $ 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    
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)         $ 17.95              
Chief Executive Officer [Member] | 2005 Stock Awards Plan [Member] | Stock Awards [Member]                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Granted (shares)             31,080          
Granted, weighted average grant date fair value (dollars per share)             $ 15.69          
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) 40,991   8,216         7,088        
Annual cash retainer fees $ 330,000   $ 119,000         $ 111,000        
Restricted Stock [Member] | Non Employee Director [Member]                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Maximum annual retainer percent                     100.00%  
Specialty Pipe And Tube, Inc. [Member] | Certain Management Employees [Member] | 2005 Stock Awards Plan [Member] | Stock Awards [Member]                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Granted (shares)           23,665            
Granted, weighted average grant date fair value (dollars per share)           $ 15.85