SHAREHOLDERS' EQUITY - (Reconciliation of Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Before Tax [Roll Forward]
Change in net unrealized losses on investments, available-for-sale	$ (1,037)	$ (2,786)	$ (6,308)
Income Tax [Roll Forward]
Other comprehensive income after reclassifications	(608)	(1,046)	(2,454)
Net [Roll Forward]
Accumulated other comprehensive income, beginning of period	1,941
Accumulated other comprehensive income, end of period	1,770	1,941
AOCI Attributable to Parent [Member]
Before Tax [Roll Forward]
Accumulated other comprehensive income, beginning of period	3,324	6,110
Other comprehensive income before reclassifications	7,511	259
Reclassification adjustment for realized gains included in net (loss) income	8,548	(3,045)
Accumulated other comprehensive income, end of period	2,287	3,324	6,110
Income Tax [Roll Forward]
Accumulated other comprehensive income, beginning of period	1,201	2,247
Other comprehensive income before reclassifications	2,640	111
Reclassification from AOCI, Current Period, Tax	3,248	1,157
Accumulated other comprehensive income, end of period	593	1,201	2,247
Net [Roll Forward]
Accumulated other comprehensive income, beginning of period	2,123	3,863
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	4,871	148
Reclassification adjustment for realized gains included in net (loss) income	(5,300)	(1,888)
Other comprehensive income after reclassifications	(429)	(1,740)
Accumulated other comprehensive income, end of period	$ 1,694	$ 2,123	$ 3,863