LOSS AND LOSS ADJUSTMENT RESERVES - (Schedule of Reconciliation of Net Incurred and Paid Development) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Liability for Claims and Claims Adjustment Expense [Abstract]
Total liabilities for unpaid losses and LAE, net of reinsurance	$ 127,791	$ 117,537
Reinsurance Recoverables on Unpaid Losses, Gross to Net [Abstract]
Total reinsurance recoverables	98,345	40,412
Unallocated loss adjustment expenses	4,379	161
Unfavorable loss and LAE reserve	230,515	158,110	$ 97,706	$ 78,330
Homeowners [Member]
Liability for Claims and Claims Adjustment Expense [Abstract]
Total liabilities for unpaid losses and LAE, net of reinsurance	99,650	87,955
Reinsurance Recoverables on Unpaid Losses, Gross to Net [Abstract]
Total reinsurance recoverables	81,852	20,968
Unfavorable loss and LAE reserve	99,650
Commercial General Liability [Member]
Liability for Claims and Claims Adjustment Expense [Abstract]
Total liabilities for unpaid losses and LAE, net of reinsurance	17,111	21,790
Reinsurance Recoverables on Unpaid Losses, Gross to Net [Abstract]
Total reinsurance recoverables	0	35
Unfavorable loss and LAE reserve	17,111
Personal Auto Liability [Member]
Liability for Claims and Claims Adjustment Expense [Abstract]
Total liabilities for unpaid losses and LAE, net of reinsurance	11,030	7,792
Reinsurance Recoverables on Unpaid Losses, Gross to Net [Abstract]
Total reinsurance recoverables	15,360	19,201
Unfavorable loss and LAE reserve	11,030
Flood Insurance [Member]
Liability for Claims and Claims Adjustment Expense [Abstract]
Total liabilities for unpaid losses and LAE, net of reinsurance	0	0
Reinsurance Recoverables on Unpaid Losses, Gross to Net [Abstract]
Total reinsurance recoverables	$ 1,133	$ 208