INCOME TAXES - Reconciliation of Statutory to Effective Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Tax benefit at statutory rate	$ 23,654	$ 11,907	$ 114,222
State tax benefit, net of federal taxes	4,587	1,398	8,414
Change in valuation allowance	41,550	(14,725)	(57,567)
Change in tax contingencies	10	66	37
Alternative minimum tax receivable	925	0	0
Corporate tax rate changes	(67,707)	0	0
Goodwill impairment	0	0	(43,362)
Other	1,111	(661)	(212)
Tax benefit (expense)	$ 4,130	$ (2,015)	$ 21,532