LONG-TERM DEBT LIABILITIES - Debt Extinguishment and Net Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net Interest Expense
Interest expense	$ 8,435	$ 8,513	$ 17,057	$ 17,004
Amortization of deferred financing costs	631	716	1,319	1,423
Amortization of original issue discount of senior notes	93	84	184	165
Interest expense on interest rate hedging agreements	0	0	0	0
Interest income and other investment income	(12)	0	(21)	0
Total net interest expense	$ 9,147	$ 9,313	$ 18,539	$ 18,592