Concentrations (Details)	12 Months Ended
	Dec. 31, 2012 Service_Center
Canadian
Concentration [Abstract]
Number of service centers	3
Chemical Industry [Member]
Concentration [Abstract]
Approximate percentage of revenue	23.00%
Petroleum Industry [Member]
Concentration [Abstract]
Approximate percentage of revenue	20.00%
Transportation Industry [Member]
Concentration [Abstract]
Approximate percentage of revenue	15.00%
Steel Industry [Member]
Concentration [Abstract]
Approximate percentage of revenue	12.00%
Food/Agriculture [Member]
Concentration [Abstract]
Approximate percentage of revenue	11.00%
Percentage of employees covered by union contracts [Member]
Concentration [Abstract]
Approximate percentage of revenue	35.00%
Percentage of employees covered by union contracts, expiring within an year [Member]
Concentration [Abstract]
Approximate percentage of revenue	4.00%