SHAREHOLDERS' EQUITY (Reconciliation of Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Before Tax [Roll Forward]
Comprehensive (loss) income before income taxes	$ (2,736)	$ 34,132	$ 40,055
Income Tax [Roll Forward]
Other comprehensive income after reclassifications	1,046	2,454	(1,102)
Net [Roll Forward]
Accumulated other comprehensive income, beginning of period	3,985
Accumulated other comprehensive income, end of period	1,941	3,985
Accumulated Other Comprehensive Income [Member]
Before Tax [Roll Forward]
Accumulated other comprehensive income, beginning of period	6,111	12,419
Other comprehensive income before reclassifications	1,774	(324)
Reclassification adjustment for realized gains included in net (loss) income	(4,560)	(5,984)
Comprehensive (loss) income before income taxes	(2,786)	(6,308)
Accumulated other comprehensive income, end of period	3,323	6,111	12,419
Income Tax [Roll Forward]
Accumulated other comprehensive income, beginning of period	(2,247)	(4,701)
Other comprehensive income before reclassifications	(470)	86
Reclassification adjustment for realized gains included in net (loss) income	1,515	2,368
Other comprehensive income after reclassifications	1,046	2,454
Accumulated other comprehensive income, end of period	(1,199)	(2,247)	(4,701)
Net [Roll Forward]
Accumulated other comprehensive income, beginning of period	3,864	7,718
Other comprehensive income before reclassifications	1,305	(238)
Reclassification adjustment for realized gains included in net (loss) income	(3,045)	(3,616)
Other comprehensive income after reclassifications	(1,740)	(3,854)
Accumulated other comprehensive income, end of period	$ 2,124	$ 3,864	$ 7,718