LOSS AND LOSS ADJUSTMENT EXPENSE RESERVES (Schedule of Incurred Losses and ALAE, Net of Reinsurance) (Details) $ in Thousands	Dec. 31, 2016 USD ($) claim $ / claim	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2008 USD ($)	Dec. 31, 2007 USD ($)
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 500,785
Accident Year 2007 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	17,559	$ 17,553	$ 17,715	$ 17,912	$ 17,761	$ 17,494	$ 17,544	$ 17,319	$ 18,293	$ 19,410
IBNR & development on reported claims	$ 6
Cumulative number of reported claims | claim	1,883
Severity | $ / claim	9,325
Accident Year 2008 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 15,609	15,604	15,661	16,021	15,659	15,977	15,811	15,784	$ 18,305
IBNR & development on reported claims	$ 4
Cumulative number of reported claims | claim	1,705
Severity | $ / claim	9,155
Accident Year 2009 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 27,163	27,119	27,041	27,015	26,482	25,955	25,618	$ 26,228
IBNR & development on reported claims	$ 101
Cumulative number of reported claims | claim	2,323
Severity | $ / claim	11,693
Accident Year 2010 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 29,945	29,407	28,968	27,895	26,151	25,056	$ 24,825
IBNR & development on reported claims	$ 34
Cumulative number of reported claims | claim	2,348
Severity | $ / claim	12,753
Accident Year 2011 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 25,957	24,582	23,932	23,007	21,344	$ 20,492
IBNR & development on reported claims	$ 40
Cumulative number of reported claims | claim	2,344
Severity | $ / claim	11,074
Accident Year 2012 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 25,889	24,468	24,186	23,301	$ 23,032
IBNR & development on reported claims	$ 326
Cumulative number of reported claims | claim	2,579
Severity | $ / claim	10,038
Accident Year 2013 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 35,859	35,834	42,021	$ 43,807
IBNR & development on reported claims	$ 216
Cumulative number of reported claims | claim	3,209
Severity | $ / claim	11,175
Accident Year 2014 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 61,770	63,300	$ 64,312
IBNR & development on reported claims	$ 2,222
Cumulative number of reported claims | claim	5,679
Severity | $ / claim	10,877
Accident Year 2015 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 92,159	$ 99,286
IBNR & development on reported claims	$ 8,097
Cumulative number of reported claims | claim	11,196
Severity | $ / claim	8,231
Accident Year 2016 [Member]
Claims Development [Line Items]
Incurred, claims and allocated claim adjustment expenses, net of reinsurance	$ 168,875
IBNR & development on reported claims	$ 48,663
Cumulative number of reported claims | claim	20,923
Severity | $ / claim	8,071