Investments (Details - cost, unrealized gains and losses and fair value) (Trading securities [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	$ 14,399,284	[1]	$ 14,804,575	[1]
Gross unrealized gains	621,505		913,765
Gross unrealized losses	(192,887)		(78,471)
Fair value	14,827,902		15,639,869
Fixed maturities [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	13,376,455	[1]	13,653,615	[1]
Gross unrealized gains	371,213		798,405
Gross unrealized losses	(154,365)		(56,705)
Fair value	13,593,303		14,395,315
Fixed maturities [Member] | US Government and government sponsored enterpises [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	1,635,578	[1]	1,108,513	[1]
Gross unrealized gains	7,211		23,173
Gross unrealized losses	(18,930)		(762)
Fair value	1,623,859		1,130,924
Fixed maturities [Member] | US states, territories and municipalities [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	121,697	[1]	232,433	[1]
Gross unrealized gains	4,395		11,057
Gross unrealized losses	(1,505)		(104)
Fair value	124,587		243,386
Fixed maturities [Member] | Non US Sovereign Government Supranational And Government Related Debt Securities [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	2,295,608	[1]	2,221,272	[1]
Gross unrealized gains	67,453		155,144
Gross unrealized losses	(9,362)		(743)
Fair value	2,353,699		2,375,673
Fixed maturities [Member] | Corporate [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	5,866,991	[1]	6,197,594	[1]
Gross unrealized gains	243,522		463,221
Gross unrealized losses	(61,850)		(4,977)
Fair value	6,048,663		6,655,838
Fixed maturities [Member] | Asset-backed securities [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	1,126,812	[1]	701,264	[1]
Gross unrealized gains	15,232		23,972
Gross unrealized losses	(3,813)		(1,766)
Fair value	1,138,231		723,470
Fixed maturities [Member] | Residential mortgage-backed securities [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	2,294,870	[1]	3,128,618	[1]
Gross unrealized gains	31,810		118,988
Gross unrealized losses	(58,163)		(47,682)
Fair value	2,268,517		3,199,924
Fixed maturities [Member] | Other mortgage-backed securities [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	34,899	[1]	63,921	[1]
Gross unrealized gains	1,590		2,850
Gross unrealized losses	(742)		(671)
Fair value	35,747		66,100
Short-term investments [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	13,543	[1]	150,634	[1]
Gross unrealized gains	4		9
Gross unrealized losses	(1)		(91)
Fair value	13,546		150,552
Equity securities [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Cost	1,009,286	[1]	1,000,326	[1]
Gross unrealized gains	250,288		115,351
Gross unrealized losses	(38,521)		(21,675)
Fair value	$ 1,221,053		$ 1,094,002

[1] Cost is amortized cost for fixed maturities and short-term investments and cost for equity securities.