LOSS AND LOSS ADJUSTMENT RESERVES (Activity in Liability for Loss and LAE Reserves) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Liability for Future Policy Benefits [Abstract]
Gross reserves, beginning-of-period	$ 296,230	$ 230,515
Less: reinsurance recoverable	(166,396)	(98,345)
Net reserves, beginning-of-period	129,834	132,170
Incurred loss, net of reinsurance, related to:
Current year	67,048	48,459
Prior year loss development	721	(653)
Ceded losses subject to offsetting experience account adjustments	(930)	(1,735)
Prior years	(209)	(2,388)
Total incurred loss and LAE, net of reinsurance	66,839	46,071
Paid loss, net of reinsurance, related to:
Current year	14,868	22,543
Prior years	41,974	30,911
Total paid loss and LAE, net of reinsurance	56,842	53,454
Net reserves, end-of-period	139,831	124,787
Plus: reinsurance recoverable	(234,293)	(111,427)
Gross reserves, end-of-period	$ 374,124	$ 236,214