LONG-TERM DEBT LIABILITIES - Debt Extinguishment and Net Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net Interest Expense
Interest expense	$ 5,579	$ 8,435	$ 10,993	$ 17,057
Amortization of deferred financing costs	580	631	1,166	1,319
Amortization of original issue discount of senior notes	0	93	0	184
Interest expense on interest rate hedging agreements	0	0
Interest income and other investment income	(26)	(12)	(49)	(21)
Total net interest expense	$ 6,133	$ 9,147	12,110	18,539
Extinguishment of Debt [Line Items]
Gains (Losses) on Extinguishment of Debt			$ 0	$ 0