Derivatives (Details - Income Statement) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
[DesignatedAsHedgingInstrumentMember] | [ForwardContractsNetInvestmentHedgeMember]
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion of net investment hedging derivatives		$ 1,200,000
[NondesignatedMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(91,065,000)	3,690,000	55,733,000
[NondesignatedMember] | [ForeignCurrencyGainLossMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	88,162,000	72,341,000	45,307,000
[NondesignatedMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(179,227,000)	(68,651,000)	10,426,000
[NondesignatedMember] | [ForeignExchangeForwardMember] | [ForeignCurrencyGainLossMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	98,089,000	65,973,000	39,573,000
[NondesignatedMember] | [ForeignExchangeOptionMember] | [ForeignCurrencyGainLossMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(9,927,000)	6,368,000	5,734,000
[NondesignatedMember] | [FutureMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(185,816,000)	(81,789,000)	(10,147,000)
[NondesignatedMember] | [CreditDefaultSwapBuyingProtectionMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(352,000)	(2,155,000)	(15,535,000)
[NondesignatedMember] | [CreditDefaultSwapSellingProtectionMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	886,000	918,000	7,062,000
[NondesignatedMember] | [InsuranceLinkedSecuritiesMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(9,584,000)	10,241,000	3,524,000
[NondesignatedMember] | [TotalReturnSwapMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	2,473,000	4,029,000	22,083,000
[NondesignatedMember] | [InterestRateSwapMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	(2,200,000)	2,374,000	4,190,000
[NondesignatedMember] | [InterestRateContractMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	0	(3,848,000)	0
[NondesignatedMember] | [OtherContractMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	0	(158,000)	107,000
[NondesignatedMember] | [ToBeAnnouncedSecuritiesMember] | [NetRealizedAndUnrealizedInvestmentGainsAndLossesMember]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain(loss) on derivatives recognized in income	$ 15,366,000	$ 1,737,000	$ (858,000)