LONG-TERM DEBT LIABILITIES - Debt Extinguishment and Net Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net Interest Expense
Interest expense	$ 25,626	$ 5,579	$ 48,960	$ 10,993
Amortization of deferred financing costs	796	580	1,591	1,166
Amortization of original issue discount of senior notes	(716)	0	(1,432)	0
Interest expense on interest rate hedging agreements	0	0
Interest income and other investment income	0	(26)	(9)	(49)
Total net interest expense	$ 25,706	$ 6,133	49,110	12,110
Extinguishment of Debt [Line Items]
Gains (Losses) on Extinguishment of Debt			$ 0	$ 0