Long-Term Debt, Capital Lease Obligation (Details) (USD $)
6 Months Ended
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Debt Disclosure [Abstract]      
Senior Notes Noncurrent Variable Rate Term Note $ 42,500,000   $ 45,000,000
Senior Notes Noncurrent Variable Rate Revolving Note 126,500,000   128,700,000
Total senior secured debt 169,000,000   173,700,000
Unsecured Debt 2,623,000   2,470,000
Capital Lease Obligations 459,000   221,000
Long-term Debt, Current Maturities (7,831,000)   (7,667,000)
Long-term debt, less current portion 164,251,000   168,724,000
Line of Credit Facility [Line Items]      
Line of Credit Facility, Maximum Borrowing Capacity 215,000,000    
Line of Credit Facility, Amendment Fees, Amount 300,000    
Lineofcreditfacilityoriginalmaximumborrowingcapacity 155,000,000    
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value 9,691,000 37,096,000 40,225,000
Act [Member]
     
Line of Credit Facility [Line Items]      
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value 1,400,000 24,644,000 24,563,000
Secured Debt [Member]
     
Line of Credit Facility [Line Items]      
Line of Credit Facility, Maximum Borrowing Capacity 50,000,000    
Line of Credit Facility, Expiration Date December 6, 2015    
Revolving Credit Facility [Member]
     
Line of Credit Facility [Line Items]      
Line of Credit Facility, Maximum Borrowing Capacity 165,000,000    
Line of Credit Facility, Expiration Date December 6, 2015    
Line Of Credit Facility Maximum Borrowing Capacity Accordion Feature $ 200,000,000