LOSS AND LOSS ADJUSTMENT RESERVES (Activity in Liability for Loss and LAE Reserves) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Liability for Future Policy Benefit, before Reinsurance [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	195,024	159,998
Prior year loss development	1,238	330
Ceded losses subject to offsetting experience account adjustments	(1,978)	(4,230)
Prior years	(740)	(3,900)
Total incurred loss and LAE, net of reinsurance	194,284	156,098
Paid loss, net of reinsurance, related to:
Current year	114,790	87,960
Prior years	77,398	71,266
Total paid loss and LAE, net of reinsurance	192,188	159,226
Net reserves, end-of-period	131,930	129,042
Plus: reinsurance recoverable	155,018	92,072
Gross reserves, end-of-period	$ 286,948	$ 221,114