LOSS AND LOSS ADJUSTMENT RESERVES (Activity in Liability for Loss and LAE Reserves) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 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	69,365	67,048
Prior year loss development	(117)	721
Ceded losses subject to offsetting experience account adjustments	(295)	(930)
Prior years	(412)	(209)
Amortization of acquisition fair value adjustment	(23)	0
Total incurred loss and LAE, net of reinsurance	68,930	66,839
Paid loss, net of reinsurance, related to:
Current year	13,371	14,868
Prior years	52,423	41,974
Total paid loss and LAE, net of reinsurance	65,794	56,842
Net reserves, end-of-period	163,069	139,831
Plus: reinsurance recoverable	212,606	234,293
Gross reserves, end-of-period	$ 375,675	$ 374,124