ACCUMULATED OTHER COMPREHENSIVE LOSS (Reclassification out of AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified out of accumulated other comprehensive loss	$ (222)	$ 0	$ 0
Unrealized (losses) gains on available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified out of accumulated other comprehensive loss	$ (222)	$ 0	$ 0