Derivatives (Details - Income Statement) ([NondesignatedMember], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	$ 7,366	$ (91,065)	$ 3,690
[ForeignCurrencyGainLossMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	27,263	88,162	72,341
[NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(19,897)	(179,227)	(68,651)
[ForeignExchangeForwardMember] | [ForeignCurrencyGainLossMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	23,474	98,089	65,973
[ForeignExchangeOptionMember] | [ForeignCurrencyGainLossMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	3,789	(9,927)	6,368
[FutureMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(31,757)	(185,816)	(81,789)
[CreditDefaultSwapBuyingProtectionMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(907)	(352)	(2,155)
[CreditDefaultSwapSellingProtectionMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	2,016	886	918
[InsuranceLinkedSecuritiesMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	4,343	(9,584)	10,241
[TotalReturnSwapMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(749)	2,473	4,029
[InterestRateSwapMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	112	(2,200)	2,374
[InterestRateContractMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	0	0	(3,848)
[OtherContractMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	0	0	(158)
[ToBeAnnouncedSecuritiesMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	$ 7,045	$ 15,366	$ 1,737