LOSS AND LOSS ADJUSTMENT RESERVES (Activity in Liability for Loss and LAE Reserves) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 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	159,998	191,747
Prior year loss development	330	8,309
Ceded losses subject to offsetting experience account adjustments	(4,230)	(11,373)
Prior years	(3,900)	(3,064)
Total incurred loss and LAE, net of reinsurance	156,098	188,683
Paid loss, net of reinsurance, related to:
Current year	87,960	109,988
Prior years	71,266	57,322
Total paid loss and LAE, net of reinsurance	159,226	167,310
Net reserves, end-of-period	129,042	139,071
Plus: reinsurance recoverable	(92,072)	(322,520)
Gross reserves, end-of-period	$ 221,114	$ 461,591