INVESTMENTS (DETAILS 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Investment Income [Line Items]
Gross investment income									$ 440,838	$ 409,088	$ 387,947
Investment expenses									(31,526)	(28,131)	(25,517)
Net investment income	113,863	103,429	83,112	108,908	86,847	103,638	74,449	116,023	409,312	380,957	362,430
Fixed Maturities [Member]
Net Investment Income [Line Items]
Gross investment income									293,609	304,400	337,616
Other Investments [Member]
Net Investment Income [Line Items]
Gross investment income									128,814	87,660	31,856
Equity Securities [Member]
Net Investment Income [Line Items]
Gross investment income									10,897	11,904	11,186
Cash And Cash Equivalents [Member]
Net Investment Income [Line Items]
Gross investment income									6,337	4,528	5,697
Short-term Investments [Member]
Net Investment Income [Line Items]
Gross investment income									$ 1,181	$ 596	$ 1,592