v2.4.0.8
Long-term Debt (Details) (USD $)
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Debt Instrument [Line Items]    
Long-term debt $ 516,453,000 $ 404,478,000
Less current installments (39,415,000) (23,796,000)
Long-term debt, less current installments 477,038,000 380,682,000
Defined events of default [Abstract]    
Threshold for outstanding obligations 3,000,000  
Threshold for judgments 750,000  
Aggregate maturities of long-term debt [Abstract]    
2014 39,415,000  
2015 39,032,000  
2016 37,613,000  
2017 295,355,000  
2018 18,294,000  
Thereafter 86,744,000  
Term loan due 2017
    
Debt Instrument [Line Items]    
Long-term debt 332,510,000 287,500,000
Interest rate (in hundredths) 2.19%  
Revolving Credit Facility Due 2017
    
Debt Instrument [Line Items]    
Long-term debt 12,000,000 67,000,000
Interest rate (in hundredths) 4.25%  
Maximum borrowing capacity 100,000,000  
Available borrowing capacity 84,500,000  
Additional amount borrowed on senior credit facility during the current period 60,000,000  
Number of letters of credit reducing available borrowing capacity under revolving credit facility 3  
Amount of letters of credit reducing available borrowing capacity under revolving credit facility 3,525,000  
Notes payable (2.31% to 6.57%) due 2014 through 2024
    
Debt Instrument [Line Items]    
Long-term debt 156,841,000 36,934,000
Interest rate, minimum (in hundredths) 2.31%  
Interest rate, maximum (in hundredths) 6.57%  
Notes payable (variable) due 2015
    
Debt Instrument [Line Items]    
Long-term debt 1,276,000 2,211,000
Interest rate (in hundredths) 4.00%  
Note payable (4.92%) due 2018
    
Debt Instrument [Line Items]    
Long-term debt 4,425,000 4,720,000
Interest rate (in hundredths) 4.92%  
Notes payable (3.55% to 4.00%) due in 2019
    
Debt Instrument [Line Items]    
Long-term debt 6,861,000 3,206,000
Interest rate, minimum (in hundredths) 3.55%  
Interest rate, maximum (in hundredths) 4.00%  
Note payable (4.04%) due 2019
    
Debt Instrument [Line Items]    
Long-term debt 2,540,000 2,907,000
Interest rate (in hundredths) 4.04%  
Senior credit facility
    
Debt Instrument [Line Items]    
Maximum additional draws on senior credit facility $ 40,000,000  
Payment terms, description Quarterly principal payments began in 2013 as follows: 1.25% of total principal balance per quarter for quarters 1 8; 1.875% of total principal balance per quarter for quarters 9 16; and 2.5% of total principal balance per quarter for quarters 17 19. All remaining principal is due at the maturity date inDecember 2017 but can be prepaid at any time without penalty  
Interest rate, description Base Rate Loans (as defined in the Amended and Restated Revolving Credit, Term Loan and Security Agreement) bear interest at the greater of (i) prime or (ii) the federal funds rate plus 0.25% to 1.25%. The interest rate for LIBOR Rate Loans (as defined in the Amended and Restated Revolving Credit, Term Loan and Security Agreement) is generally the LIBOR rate plus 1.25% to 2.25  
Percentage of principal balance payments per quarter for quarters 1 - 8 (in hundredths) 1.25%  
Percentage of principal balance payments per quarter for quarters 9 - 16 (in hundredths) 1.875%  
Percentage of principal balance payments per quarter for quarters 17 - 19 (in hundredths) 2.50%  
Senior credit facility | Minimum | Federal Funds Rate
    
Debt Instrument [Line Items]    
Basis spread on variable rate (in hundredths) 0.25%  
Senior credit facility | Minimum | LIBOR Rate
    
Debt Instrument [Line Items]    
Basis spread on variable rate (in hundredths) 1.25%  
Senior credit facility | Maximum | Federal Funds Rate
    
Debt Instrument [Line Items]    
Basis spread on variable rate (in hundredths) 1.25%  
Senior credit facility | Maximum | LIBOR Rate
    
Debt Instrument [Line Items]    
Basis spread on variable rate (in hundredths) 2.25%