ACCUMULATED OTHER COMPREHENSIVE LOSS (Reclassified Out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Unrealized holding gains on available-for-sale investments	$ (833)	$ (189)	$ (2,382)	$ (539)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Unrealized holding gains on available-for-sale investments	$ 76	$ 0	$ 222	$ 0