ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Rollforward of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income before reclassifications	$ (693)
Amounts reclassified from accumulated other comprehensive income (loss)	(332)	$ 1,601	$ 19,828
Change in accumulated other comprehensive income (loss)	(1,025)
AOCI Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2016	1,405
Balance as of December 31, 2017	$ 380	$ 1,405