v2.4.0.6
FAIR VALUE OF FINANCIAL INSTRUMENTS - Carrying Value (Details) (USD $)
In Thousands, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Line of Credit [Member]
   
Fair Value Of Instruments [Line Items]    
Carrying value of debt $ 357,500 $ 385,000
Fair value of debt 359,734 385,000
Senior Notes [Member]
   
Fair Value Of Instruments [Line Items]    
Carrying value of debt 217,223 217,103
Fair value of debt 231,886 216,696
Finance Method Lease Obligations [Member]
   
Fair Value Of Instruments [Line Items]    
Carrying value of debt 12,610 12,610
Letter of credit [Member]
   
Fair Value Of Instruments [Line Items]    
Carrying value of debt $ 570 $ 570