| Schedule of net sales to unaffiliated customers and identifiable assets by geographic areas | 
        
   
  
| 
   
 | 
   
 | 
 2012 
 | 
   
 | 
 2011 
 | 
   
 | 
 2010 
 | 
   
 | 
 
| 
 Net sales to Unaffiliated Customers: 
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 United States 
 | 
   
 | 
 $ 
 | 
 251,991 
 | 
   
 | 
 $ 
 | 
 209,946 
 | 
   
 | 
 $ 
 | 
 174,180 
 | 
   
 | 
 
| 
 Canada 
 | 
   
 | 
 22,245 
 | 
   
 | 
 18,672 
 | 
   
 | 
 15,048 
 | 
   
 | 
 
| 
 Other 
 | 
   
 | 
 22,821 
 | 
   
 | 
 21,551 
 | 
   
 | 
 17,502 
 | 
   
 | 
 
| 
 Total 
 | 
   
 | 
 $ 
 | 
 297,057 
 | 
   
 | 
 $ 
 | 
 250,169 
 | 
   
 | 
 $ 
 | 
 206,730 
 | 
   
 | 
 
 
  
| 
   
 | 
   
 | 
 2012 
 | 
   
 | 
 2011 
 | 
   
 | 
 2010 
 | 
   
 | 
 
| 
 Identifiable Assets by Geographic Areas at December 31, 
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 United States 
 | 
   
 | 
 $ 
 | 
 85,503 
 | 
   
 | 
 $ 
 | 
 69,309 
 | 
   
 | 
 $ 
 | 
 64,237 
 | 
   
 | 
 
| 
 Canada 
 | 
   
 | 
 5,942 
 | 
   
 | 
 5,552 
 | 
   
 | 
 4,446 
 | 
   
 | 
 
| 
 Total 
 | 
   
 | 
 $ 
 | 
 91,445 
 | 
   
 | 
 $ 
 | 
 74,861 
 | 
   
 | 
 $ 
 | 
 68,683 
 | 
   
 | 
 
 
 | 
      
      
        | Schedule of segment reporting information | 
        
   
  
| 
   
 | 
   
 | 
 Year ended 
 December 31, 
 | 
   
 | 
 
| 
   
 | 
   
 | 
 2012 
 | 
   
 | 
 2011 
 | 
   
 | 
 2010 
 | 
   
 | 
 
| 
 Revenue: 
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Lifeboat Distribution 
 | 
   
 | 
 $ 
 | 
 217,342 
 | 
   
 | 
 $ 
 | 
 192,720 
 | 
   
 | 
 $ 
 | 
 149,151 
 | 
   
 | 
 
| 
 TechXtend 
 | 
   
 | 
 79,715 
 | 
   
 | 
 57,449 
 | 
   
 | 
 57,579 
 | 
   
 | 
 
| 
   
 | 
   
 | 
 297,057 
 | 
   
 | 
 250,169 
 | 
   
 | 
 206,730 
 | 
   
 | 
 
| 
 Gross Profit: 
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Lifeboat Distribution 
 | 
   
 | 
 $ 
 | 
 15,818 
 | 
   
 | 
 $ 
 | 
 16,804 
 | 
   
 | 
 $ 
 | 
 13,703 
 | 
   
 | 
 
| 
 TechXtend 
 | 
   
 | 
 8,074 
 | 
   
 | 
 6,437 
 | 
   
 | 
 6,307 
 | 
   
 | 
 
| 
   
 | 
   
 | 
 23,892 
 | 
   
 | 
 23,241 
 | 
   
 | 
 20,010 
 | 
   
 | 
 
| 
 Direct Costs: 
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Lifeboat Distribution 
 | 
   
 | 
 $ 
 | 
 4,512 
 | 
   
 | 
 $ 
 | 
 4,715 
 | 
   
 | 
 $ 
 | 
 3,934 
 | 
   
 | 
 
| 
 TechXtend 
 | 
   
 | 
 3,567 
 | 
   
 | 
 3,058 
 | 
   
 | 
 2,932 
 | 
   
 | 
 
| 
   
 | 
   
 | 
 8,079 
 | 
   
 | 
 7,773 
 | 
   
 | 
 6,866 
 | 
   
 | 
 
| 
 Segment Income Before Taxes: 
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Lifeboat Distribution 
 | 
   
 | 
 $ 
 | 
 11,306 
 | 
   
 | 
 $ 
 | 
 12,089 
 | 
   
 | 
 $ 
 | 
 9,769 
 | 
   
 | 
 
| 
 TechXtend 
 | 
   
 | 
 4,507 
 | 
   
 | 
 3,379 
 | 
   
 | 
 3,375 
 | 
   
 | 
 
| 
 Segment Income Before Taxes 
 | 
   
 | 
 15,813 
 | 
   
 | 
 15,468 
 | 
   
 | 
 13,144 
 | 
   
 | 
 
| 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 General and administrative 
 | 
   
 | 
 7,298 
 | 
   
 | 
 6,850 
 | 
   
 | 
 6,341 
 | 
   
 | 
 
| 
 Interest income 
 | 
   
 | 
 557 
 | 
   
 | 
 368 
 | 
   
 | 
 405 
 | 
   
 | 
 
| 
 Foreign currency translation gains 
 | 
   
 | 
 17 
 | 
   
 | 
 1 
 | 
   
 | 
 2 
 | 
   
 | 
 
| 
 Income before taxes 
 | 
   
 | 
 $ 
 | 
 9,089 
 | 
   
 | 
 $ 
 | 
 8,987 
 | 
   
 | 
 $ 
 | 
 7,210 
 | 
   
 | 
 
| 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Selected Assets By Segment: 
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Lifeboat Distribution 
 | 
   
 | 
 $ 
 | 
 30,258 
 | 
   
 | 
 $ 
 | 
 29,314 
 | 
   
 | 
   
 | 
 
| 
 TechXtend 
 | 
   
 | 
 44,698 
 | 
   
 | 
 27,881 
 | 
   
 | 
   
 | 
 
| 
 Segment Select Assets 
 | 
   
 | 
 74,956 
 | 
   
 | 
 57,195 
 | 
   
 | 
   
 | 
 
| 
 Corporate Assets 
 | 
   
 | 
 16,489 
 | 
   
 | 
 17,666 
 | 
   
 | 
   
 | 
 
| 
 Total Assets 
 | 
   
 | 
 $ 
 | 
 91,445 
 | 
   
 | 
 $ 
 | 
 74,861 
 | 
   
 | 
   
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 
 
 |