INVESTMENTS (DETAILS) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 11,987,146	$ 11,605,672
Gross Unrealized Gains (fixed maturities)	179,218	340,862
Gross Unrealized Losses (fixed maturities)	(180,037)	(18,485)
Fair Value (fixed maturities)	11,986,327	11,928,049
Non-credit OTTI in AOCI	(868)	(884)
Cost	566,219	608,306
Gross Unrealized Gains (equities)	141,951	65,640
Gross Unrealized Losses (equities)	(6,183)	(7,398)
Fair Value (equities)	701,987	666,548
US Government and Agency [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	1,421,245	1,413,520
Gross Unrealized Gains (fixed maturities)	1,405	9,484
Gross Unrealized Losses (fixed maturities)	(33,952)	(119)
Fair Value (fixed maturities)	1,388,698	1,422,885
Non-credit OTTI in AOCI	0	0
Non-US Government [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	1,208,384	1,076,501
Gross Unrealized Gains (fixed maturities)	17,990	30,276
Gross Unrealized Losses (fixed maturities)	(49,992)	(2,201)
Fair Value (fixed maturities)	1,176,382	1,104,576
Non-credit OTTI in AOCI	0	0
Corporate Debt [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	3,533,585	3,746,616
Gross Unrealized Gains (fixed maturities)	84,881	135,658
Gross Unrealized Losses (fixed maturities)	(10,228)	(5,892)
Fair Value (fixed maturities)	3,608,238	3,876,382
Non-credit OTTI in AOCI	0	0
Agency RMBS [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	2,485,139	2,594,180
Gross Unrealized Gains (fixed maturities)	21,979	67,398
Gross Unrealized Losses (fixed maturities)	(58,291)	(1,670)
Fair Value (fixed maturities)	2,448,827	2,659,908
Non-credit OTTI in AOCI	0	0
CMBS [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	790,095	814,211
Gross Unrealized Gains (fixed maturities)	11,285	25,999
Gross Unrealized Losses (fixed maturities)	(3,966)	(126)
Fair Value (fixed maturities)	797,414	840,084
Non-credit OTTI in AOCI	0	0
Non-Agency RMBS [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	65,590	93,266
Gross Unrealized Gains (fixed maturities)	2,375	2,503
Gross Unrealized Losses (fixed maturities)	(398)	(570)
Fair Value (fixed maturities)	67,567	95,199
Non-credit OTTI in AOCI	(868)	(884)
ABS [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	955,274	639,614
Gross Unrealized Gains (fixed maturities)	6,871	10,774
Gross Unrealized Losses (fixed maturities)	(8,694)	(7,182)
Fair Value (fixed maturities)	953,451	643,206
Non-credit OTTI in AOCI	0	0
Municipals [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	1,527,834	1,227,764
Gross Unrealized Gains (fixed maturities)	32,432	58,770
Gross Unrealized Losses (fixed maturities)	(14,516)	(725)
Fair Value (fixed maturities)	1,545,750	1,285,809
Non-credit OTTI in AOCI	0	0
Common Stock [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	345,759	398,975
Gross Unrealized Gains (equities)	98,742	51,821
Gross Unrealized Losses (equities)	(6,183)	(7,398)
Fair Value (equities)	438,318	443,398
Exchange-Traded Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	106,762	109,434
Gross Unrealized Gains (equities)	32,085	9,727
Gross Unrealized Losses (equities)	0	0
Fair Value (equities)	138,847	119,161
Non-U.S. Bond Mutual Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	113,698	99,897
Gross Unrealized Gains (equities)	11,124	4,092
Gross Unrealized Losses (equities)	0	0
Fair Value (equities)	$ 124,822	$ 103,989