INCOME TAXES - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current	$ (1,719)	$ 5,439	$ 6,368
Deferred tax benefit	(4,474)	(1,582)	(1,785)
Writedown of net deferred tax asset resulting from the Tax Cuts and Jobs Act	3,595	0	0
Total income tax (benefit) expense	$ (2,598)	$ 3,857	$ 4,583