SHAREHOLDERS' EQUITY - (Reconciliation of Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018	Jan. 01, 2017
Net [Roll Forward]
Accumulated other comprehensive income, beginning of period	$ 1,770
Accumulated other comprehensive income, end of period	(3,750)	$ 1,770
AOCI Attributable to Parent [Member]
Before Tax [Roll Forward]
Accumulated other comprehensive income, beginning of period	2,287	3,324
Cumulative effect of new accounting standards, before tax			$ (1,349)	$ 0
Other comprehensive income before reclassifications	(8,747)	7,511
Reclassification adjustment for realized gains included in net (loss) income	2,786	(8,548)
Change in net unrealized losses on investments, available-for-sale	(5,961)	(1,037)
Accumulated other comprehensive income, end of period	(5,023)	2,287
Income Tax [Roll Forward]
Accumulated other comprehensive income, beginning of period	593	1,201
Cumulative Effect Of New Accounting Principle In Period Of Adoption, Tax			355	0
Other comprehensive income before reclassifications	(2,217)	2,640
Reclassification from AOCI, Current Period, Tax	(706)	3,248
Other comprehensive income after reclassifications	1,511	608
Accumulated other comprehensive income, end of period	(1,273)	593
Net [Roll Forward]
Accumulated other comprehensive income, beginning of period	1,694	2,123
Cumulative effect of new accounting standards			$ (994)	$ 0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(6,530)	4,871
Reclassification adjustment for realized gains included in net (loss) income	2,080	(5,300)
Other comprehensive income after reclassifications	(4,450)	(429)
Accumulated other comprehensive income, end of period	$ (3,750)	$ 1,694