SUMMARY OF INVESTMENTS (Net Investment Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Other	$ 1,998		$ 1,632		$ 825
Total investment income	110,925		118,123		118,069
Less investment expense	6,316		5,324		6,164
Net Investment income	104,609		112,799		111,905
Fixed Maturities [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	97,969		101,950		108,517
Equity Securities [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Dividend income	6,602		5,806		5,354
Other Long-term Investments [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	1,927		1,194		232
Other Long-term Investments [Member] | Change in Value [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Other	1,917	[1]	7,030	[1]	2,562	[1]
Mortgage Backed Securities [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	252		266		279
Short-term Investments [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	5		6		10
Cash and Cash Equivalents [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Interest income	$ 255		$ 239		$ 290

[1] Represents the change in value of our interests in limited liability partnerships that are recorded on the equity method of accounting.