FAIR VALUE OF FINANCIAL INSTRUMENTS - Carrying Value (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Senior Notes
Fair Value Of Instruments [Line Items]
Carrying value of debt	$ 218,180	$ 217,929
Fair value of debt	230,180	237,134
Finance Method Lease Obligations
Fair Value Of Instruments [Line Items]
Carrying value of debt	0	0
Letter of credit
Fair Value Of Instruments [Line Items]
Carrying value of debt	670	620
Revolver, due November 23, 2016 [Member]
Fair Value Of Instruments [Line Items]
Carrying value of debt	39,000	0
Fair value of debt	39,000	0
Term Loan B [Member]
Fair Value Of Instruments [Line Items]
Carrying value of debt	247,750	262,000
Fair value of debt	$ 247,440	$ 261,345