Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Details Textual)

v2.4.0.6
Long-Term Debt (Details Textual) (USD $)
 3 Months Ended 1 Months Ended 3 Months Ended 3 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Mar. 31, 2011
New Credit Facility [Member]
Mar. 31, 2012
New Credit Facility [Member]
Dec. 31, 2011
New Credit Facility [Member]
Mar. 09, 2011
New Credit Facility [Member]
Mar. 31, 2012
New Credit Facility [Member]
Maximum [Member]
Mar. 31, 2012
New Credit Facility [Member]
Minimum [Member]
Mar. 31, 2012
Secured Debt [Member]
New Credit Facility [Member]
Dec. 31, 2011
Secured Debt [Member]
Prior Credit Facility [Member]
Long-Term Debt (Textual) [Abstract]                    
Senior secured revolving credit facility           $ 700,000,000        
Credit facility maturity 5 years                  
New Credit Facility, maturity date       March 9, 2016            
Margin portion of interest rate in addition to LIBOR rate             2.50% 1.50%    
Margin portion of interest rate in addition to base rate             1.50% 0.50%    
Line of credit facility, unused capacity, commitment fee percentage             0.50% 0.25%    
Additional interest rate to federal funds rate       0.50%            
Additional interest rate to LIBOR       1.00%            
Repayment of all amounts outstanding under the prior credit facility by using borrowings under the new credit facility     196,000,000              
Long-term debt, weighted average interest rate                 1.72% 1.89%
Borrowings under long-term lines of credit       112,000,000            
Repayments of long-term lines of credit       86,000,000            
Borrowings under credit facility       228,000,000 202,000,000          
Foreign currency borrowings outstanding       0 0          
Additional Long-Term Debt (Textual) [Abstract]                    
Debt issuance costs 5,700,000                  
Interest expense 2,900,000 3,300,000                
Write-off of deferred financing costs   $ 914,000