LOSS AND LOSS ADJUSTMENT RESERVES (Activity in Liability for Loss and LAE Reserves) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves, beginning-of-period	$ 324,362	$ 296,230
Less: reinsurance recoverable	(164,429)	(166,396)
Net reserves, beginning-of-period	159,933	129,834
Incurred loss, net of reinsurance, related to:
Current year	192,109	132,087
Prior year loss development	7,340	1,524
Ceded losses subject to offsetting experience account adjustments	(528)	(1,432)
Prior years	6,812	92
Amortization of acquisition fair value adjustment	(75)	0
Total incurred loss and LAE, net of reinsurance	198,846	132,179
Paid loss, net of reinsurance, related to:
Current year	75,612	69,248
Prior years	78,475	64,830
Total paid loss and LAE, net of reinsurance	154,087	134,078
Net reserves, end-of-period	204,692	127,935
Plus: reinsurance recoverable	183,031	140,800
Gross reserves, end-of-period	$ 387,723	$ 268,735