VARIABLE INTEREST ENTITY (Carrying Amount of VIE Consolidated Assets and Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Investments
Debt securities - available-for-sale, at fair value:	$ 425,489	$ 423,238
Equity securities, at fair value	17,383	15,434
Total investments (including $0 and $26,284 related to the VIE, respectively)	448,160	444,021
Cash and cash equivalents	83,924	86,228	$ 99,529	$ 74,593
Reinsurance recoverable	208,287	124,601
Prepaid reinsurance premiums	101,107	135,492
Premiums receivable, net	43,032	46,393
Deferred acquisition costs	42,920	40,893
Other assets	11,917	13,403
Total assets	951,843	904,873
Liabilities
Loss and loss adjustment expense reserves	291,675	230,515	$ 156,173	$ 158,110
Unearned premiums	302,295	294,423
Reinsurance payable	64,220	71,944
Debt, net of deferred financing costs	44,353	49,251
Other liabilities	27,990	25,059
Total liabilities	736,815	677,414
Monarch Delaware - Variable Interest Entity
Investments
Debt securities - available-for-sale, at fair value:		25,111
Equity securities, at fair value		1,173
Total investments (including $0 and $26,284 related to the VIE, respectively)	0	26,284
Cash and cash equivalents	0	14,211
Reinsurance recoverable		3,323
Prepaid reinsurance premiums		2,481
Premiums receivable, net	0	1,184
Deferred acquisition costs		1,722
Other assets	$ 0	2,322
Total assets		51,527
Liabilities
Loss and loss adjustment expense reserves		6,356
Unearned premiums		8,752
Reinsurance payable		1,802
Debt, net of deferred financing costs		4,930
Other liabilities		1,825
Total liabilities		$ 23,665