Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Details Textual)

v2.4.0.6
Long-Term Debt (Details Textual) (USD $)
 1 Months Ended 3 Months Ended 6 Months Ended
Mar. 31, 2011
Jun. 30, 2012
Mar. 31, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Dec. 31, 2011
Mar. 09, 2011
Long-Term Debt (Textual) [Abstract]                
New senior secured revolving credit facility               $ 700,000,000
Credit facility maturity         5 years      
Term loan maturity date         Mar. 09, 2016      
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 Credit Facility 196,000,000              
Company borrowing from credit facility   692,000,000 112,000,000          
Payment of credit facility   365,000,000 86,000,000          
U.S. dollar amount outstanding under the Credit Facility   555,000,000     555,000,000   202,000,000  
Foreign currency borrowings outstanding   0     0   0  
Additional Long-Term Debt (Textual) [Abstract]                
Debt issuance costs in connection with term loan   5,700,000     5,700,000      
Interest expense   4,500,000   3,100,000 7,300,000 6,400,000    
Write-off of deferred financing costs           $ 914,000    
Maximum [Member]
                
Long-Term Debt (Textual) [Abstract]                
Margin portion of interest rate in addition to LIBOR rate         2.50%      
Margin portion of interest rate in addition to base rate         1.50%      
Line of credit facility, unused capacity, commitment fee percentage         0.50%      
Minimum [Member]
                
Long-Term Debt (Textual) [Abstract]                
Margin portion of interest rate in addition to LIBOR rate         1.50%      
Margin portion of interest rate in addition to base rate         0.50%      
Line of credit facility, unused capacity, commitment fee percentage         0.25%      
Secured Debt [Member]
                
Long-Term Debt (Textual) [Abstract]                
Long-term debt, weighted average interest rate   1.74%     1.74%   1.89%