LOSS AND LOSS ADJUSTMENT RESERVES (Activity in Liability for Loss and LAE Reserves) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Liability for Future Policy Benefits [Abstract]
Gross reserves, beginning-of-period	$ 230,515	$ 158,110
Less: reinsurance recoverable	(98,345)	(40,412)
Net reserves, beginning-of-period	132,170	117,698
Incurred loss, net of reinsurance, related to:
Current year	98,132	114,779
Prior year loss development	(1,192)	7,420
Ceded losses subject to offsetting experience account adjustments	(3,299)	(8,883)
Prior years	(4,491)	(1,463)
Total incurred loss and LAE, net of reinsurance	93,641	113,316
Paid loss, net of reinsurance, related to:
Current year	42,260	48,747
Prior years	57,569	55,719
Total paid loss and LAE, net of reinsurance	99,829	104,466
Net reserves, end-of-period	125,982	126,548
Plus: reinsurance recoverable	(165,693)	(29,625)
Gross reserves, end-of-period	$ 291,675	$ 156,173