SUMMARY OF INVESTMENTS (Net Investment Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Other	$ 300	$ 422	$ 433
Total investment income from continuing operations	57,495	61,794	52,463
Less investment expenses	6,305	6,510	5,904
Net investment income from continuing operations	51,190	55,284	46,559
Discontinued Operations
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Net investment income from continuing operations	49,720	51,538	54,222
Continuing and Discontinuing Operations
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Net investment income from continuing operations	100,910	106,822	100,781
Fixed Maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	44,784	43,147	41,859
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Dividends on equity securities	7,108	6,448	6,421
Other long-term investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	6,870	1,200	1,200
Other long-term investments | Change in Value
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Other	(2,812)	10,178	2,313
Short-term investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	120	47	3
Cash and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	$ 1,125	$ 352	$ 234