Quarterly report pursuant to Section 13 or 15(d)

Debt (Details)

v2.4.0.6
Debt (Details) (USD $)
 3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Dec. 31, 2011
Debt Instrument [Line Items]          
Debt Instrument, Maturity Date     Jun. 30, 2016    
Financing costs     $ 1,700,000    
Debt outstanding 159,500,000   159,500,000   164,200,000
Debt Instrument, Description of Variable Rate Basis     LIBOR base margin 0.75%    
Debt Instrument, Basis Spread on Variable Rate 2.50%   2.50%    
Interest rate range, minimum (in hundredths)     2.49%    
Interest rate range, maximum (in hundredths)     4.12%    
Effective interest rate (in hundredths) 3.52%   3.52%    
Interest expense, net 1,200,000 448,000 2,500,000 614,000  
Term loan [Member]
          
Debt Instrument [Line Items]          
Borrowings outstanding 101,500,000   101,500,000   110,900,000
Term loan payments, 2012 9,400,000   9,400,000    
Term loan payments 2013 23,400,000   23,400,000    
Term loan payments 2014 25,000,000   25,000,000    
Term loan payments 2015 34,300,000   34,300,000    
Term loan payments 2016 9,400,000   9,400,000    
Duration of interest rate cash flow hedge (in years)     3 years    
Amount of interest rate hedge         101,000,000
Effective interest rate on the hedged term debt     0.56% plus base margin    
Letters of Credit [Member]
          
Debt Instrument [Line Items]          
Letters of credit outstanding 5,000,000   5,000,000   5,000,000
Revolving Loans [Member]
          
Debt Instrument [Line Items]          
Revolving loans maximum borrowing capacity 125,000,000   125,000,000    
Revolving loans potential increment in maximum borrowing capacity     175,000,000    
Revolving loans amount outstanding 58,000,000   58,000,000   53,300,000
Duration of interest rate cash flow hedge (in years)     2 years    
Amount of interest rate hedge $ 20,000,000   $ 20,000,000   $ 40,000,000
Effective interest rate on the hedged term debt     0.7775% plus base margin