Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies (Details)

Commitments and Contingencies (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Jun. 30, 2013
Mar. 31, 2013
Jun. 30, 2013
Notice of Tax Dispute with the Canada Revenue Agency
Commitments and Contingencies      
Totaled arrangements under letter of credit guarantees and performance bonds securing performance obligations $ 14,276    
Guarantee obligations secured by cash deposits 1,691    
Guarantee obligations represented by a reduction of the available amount of the company's short term and long term revolving lines of credit 12,586    
Cash deposits pledged as collateral on performance bonds and letters of credit 1,691 1,978  
Tax due that is requested by the Agency     $ 3,000