v2.4.0.6
FAIR VALUE OF FINANCIAL INSTRUMENTS - Carrying Value (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Line of Credit [Member]
   
Fair Value Of Instruments [Line Items]    
Carrying value of debt $ 331,722 $ 352,500
Fair value of debt 336,698 356,686
Senior Notes [Member]
   
Fair Value Of Instruments [Line Items]    
Carrying value of debt 217,415 217,349
Fair value of debt 249,484 241,257
Capital 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 $ 370 $ 570