Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	$ 13,680,838	$ 14,395,315
Short-term investments, trading securities, at fair value	36,781	150,552
Equities, trading securities	1,122,084	1,094,002
Other invested assets	34,249	71,204
Funds held - directly managed	637,830	833,247
Total	15,511,782	16,544,320
[ShortTermInvestmentsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	2,389
[DerivativeFinancialInstrumentsAssetsMember] | [ForeignExchangeForwardMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	4,188	7,889
[DerivativeFinancialInstrumentsAssetsMember] | [ForeignExchangeOptionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		1,410
[DerivativeFinancialInstrumentsAssetsMember] | [FutureMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		1,956
[DerivativeFinancialInstrumentsAssetsMember] | [CreditDefaultSwapBuyingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		6
[DerivativeFinancialInstrumentsAssetsMember] | [CreditDefaultSwapSellingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	49	512
[DerivativeFinancialInstrumentsAssetsMember] | [InsuranceLinkedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	175
[DerivativeFinancialInstrumentsAssetsMember] | [TotalReturnSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		6,630
[DerivativeFinancialInstrumentsAssetsMember] | [InterestRateSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	150
[DerivativeFinancialInstrumentsAssetsMember] | [ToBeAnnouncedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	7,256	115
[DerivativeFinancialInstrumentsLiabilitiesMember] | [ForeignExchangeForwardMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(5,470)	(17,395)
[DerivativeFinancialInstrumentsLiabilitiesMember] | [ForeignExchangeOptionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(821)	(186)
[DerivativeFinancialInstrumentsLiabilitiesMember] | [FutureMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(61,909)	(1,352)
[DerivativeFinancialInstrumentsLiabilitiesMember] | [CreditDefaultSwapBuyingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(231)	(807)
[DerivativeFinancialInstrumentsLiabilitiesMember] | [InsuranceLinkedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(390)	(2,173)
[DerivativeFinancialInstrumentsLiabilitiesMember] | [TotalReturnSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(732)	(546)
[DerivativeFinancialInstrumentsLiabilitiesMember] | [InterestRateSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(4,614)	(7,880)
[DerivativeFinancialInstrumentsLiabilitiesMember] | [ToBeAnnouncedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		(163)
[OtherInvestedAssetsNotesAndLoanReceivablesAndNotesSecuritizationMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	47,781	34,902
[OtherInvestedAssetsAnnuitiesAndResidualsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	26,939	46,882
[PrivateEquitiesTotalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	21,878	1,404
[OtherInvestedAssetsFundsHeldDirectlyManagedMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	15,566	17,976
[RealEstateInvestmentMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	168,985	66,846
[EnergyMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	156,254	118,213
[FinanceMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	129,367	100,405
[ConsumerNoncyclicalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	119,194	130,526
[CommunicationsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	66,169	65,722
[TechnologyMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	60,685	78,914
[IndustrialsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	45,181	59,242
[ConsumerCyclicalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	44,566	62,526
[PublicUtilityEquitiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	38,481
[InsuranceMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	36,481	39,132
[OtherEquitiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	20,559	60,913
[MutualFundsAndExchangeTradedFundsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	236,162	311,563
[USTreasuryAndGovernmentMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	1,495,749	1,130,924
Funds held - directly managed	167,808	218,696
[USStatesAndPoliticalSubdivisionsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	305,794	243,386
Funds held - directly managed	298	345
[NonUsSovereignGovernmentSupranationalAndGovernmentRelatedMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	2,343,751	2,375,673
Funds held - directly managed	192,823	233,987
[CorporateDebtSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	6,041,986	6,655,838
Funds held - directly managed	258,946	362,243
[AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	1,157,927	723,470
[ResidentialMortgageBackedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	2,293,874	3,199,924
[CommercialMortgageBackedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	41,757	66,100
[FairValueInputsLevel1Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
Short-term investments, trading securities, at fair value	0	0
Equities, trading securities	898,413	788,556
Other invested assets	(61,909)	604
Funds held - directly managed	0	0
Total	836,504	789,160
[FairValueInputsLevel1Member] | [ShortTermInvestmentsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ForeignExchangeForwardMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ForeignExchangeOptionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [FutureMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		1,956
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [CreditDefaultSwapBuyingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [CreditDefaultSwapSellingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [InsuranceLinkedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [TotalReturnSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [InterestRateSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ToBeAnnouncedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ForeignExchangeForwardMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ForeignExchangeOptionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [FutureMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(61,909)	(1,352)
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [CreditDefaultSwapBuyingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [InsuranceLinkedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [TotalReturnSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [InterestRateSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ToBeAnnouncedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel1Member] | [OtherInvestedAssetsNotesAndLoanReceivablesAndNotesSecuritizationMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [OtherInvestedAssetsAnnuitiesAndResidualsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [PrivateEquitiesTotalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel1Member] | [OtherInvestedAssetsFundsHeldDirectlyManagedMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	0	0
[FairValueInputsLevel1Member] | [RealEstateInvestmentMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	168,985	66,846
[FairValueInputsLevel1Member] | [EnergyMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	156,254	118,213
[FairValueInputsLevel1Member] | [FinanceMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	105,025	79,456
[FairValueInputsLevel1Member] | [ConsumerNoncyclicalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	119,194	130,526
[FairValueInputsLevel1Member] | [CommunicationsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	64,026	65,722
[FairValueInputsLevel1Member] | [TechnologyMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	51,535	71,927
[FairValueInputsLevel1Member] | [IndustrialsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	45,181	59,242
[FairValueInputsLevel1Member] | [ConsumerCyclicalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	44,566	62,526
[FairValueInputsLevel1Member] | [PublicUtilityEquitiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	38,481
[FairValueInputsLevel1Member] | [InsuranceMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	36,481	39,132
[FairValueInputsLevel1Member] | [OtherEquitiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	20,559	60,913
[FairValueInputsLevel1Member] | [MutualFundsAndExchangeTradedFundsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	48,126	34,053
[FairValueInputsLevel1Member] | [USTreasuryAndGovernmentMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
Funds held - directly managed	0	0
[FairValueInputsLevel1Member] | [USStatesAndPoliticalSubdivisionsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
Funds held - directly managed	0	0
[FairValueInputsLevel1Member] | [NonUsSovereignGovernmentSupranationalAndGovernmentRelatedMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
Funds held - directly managed	0	0
[FairValueInputsLevel1Member] | [CorporateDebtSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
Funds held - directly managed	0	0
[FairValueInputsLevel1Member] | [AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
[FairValueInputsLevel1Member] | [ResidentialMortgageBackedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
[FairValueInputsLevel1Member] | [CommercialMortgageBackedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
[FairValueInputsLevel2Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	12,838,323	13,738,042
Short-term investments, trading securities, at fair value	36,781	150,552
Equities, trading securities	190,419	277,718
Other invested assets	507	(16,499)
Funds held - directly managed	621,966	814,926
Total	13,687,996	14,964,739
[FairValueInputsLevel2Member] | [ShortTermInvestmentsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	2,389
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ForeignExchangeForwardMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	4,188	7,889
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ForeignExchangeOptionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		1,410
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [FutureMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [CreditDefaultSwapBuyingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		6
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [CreditDefaultSwapSellingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	49	512
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [InsuranceLinkedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [TotalReturnSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [InterestRateSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	150
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ToBeAnnouncedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	7,256	115
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ForeignExchangeForwardMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(5,470)	(17,395)
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ForeignExchangeOptionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(821)	(186)
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [FutureMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [CreditDefaultSwapBuyingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(231)	(807)
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [InsuranceLinkedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [TotalReturnSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [InterestRateSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(4,614)	(7,880)
[FairValueInputsLevel2Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ToBeAnnouncedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		(163)
[FairValueInputsLevel2Member] | [OtherInvestedAssetsNotesAndLoanReceivablesAndNotesSecuritizationMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel2Member] | [OtherInvestedAssetsAnnuitiesAndResidualsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel2Member] | [PrivateEquitiesTotalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel2Member] | [OtherInvestedAssetsFundsHeldDirectlyManagedMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	0	0
[FairValueInputsLevel2Member] | [RealEstateInvestmentMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [EnergyMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [FinanceMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	10,057	7,472
[FairValueInputsLevel2Member] | [ConsumerNoncyclicalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [CommunicationsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [TechnologyMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [IndustrialsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [ConsumerCyclicalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [PublicUtilityEquitiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0
[FairValueInputsLevel2Member] | [InsuranceMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [OtherEquitiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel2Member] | [MutualFundsAndExchangeTradedFundsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	180,362	270,246
[FairValueInputsLevel2Member] | [USTreasuryAndGovernmentMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	1,495,749	1,130,924
Funds held - directly managed	167,808	218,696
[FairValueInputsLevel2Member] | [USStatesAndPoliticalSubdivisionsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	16,659	10,151
Funds held - directly managed	0	0
[FairValueInputsLevel2Member] | [NonUsSovereignGovernmentSupranationalAndGovernmentRelatedMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	2,343,751	2,375,673
Funds held - directly managed	192,823	233,987
[FairValueInputsLevel2Member] | [CorporateDebtSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	5,942,359	6,554,934
Funds held - directly managed	258,946	362,243
[FairValueInputsLevel2Member] | [AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	704,174	400,336
[FairValueInputsLevel2Member] | [ResidentialMortgageBackedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	2,293,874	3,199,924
[FairValueInputsLevel2Member] | [CommercialMortgageBackedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	41,757	66,100
[FairValueInputsLevel3Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	842,515	657,273
Short-term investments, trading securities, at fair value	0	0
Equities, trading securities	33,252	27,728
Other invested assets	95,651	87,099
Funds held - directly managed	15,864	18,321
Total	987,282	790,421
[FairValueInputsLevel3Member] | [ShortTermInvestmentsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ForeignExchangeForwardMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ForeignExchangeOptionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [FutureMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [CreditDefaultSwapBuyingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [CreditDefaultSwapSellingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [InsuranceLinkedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	175
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [TotalReturnSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		6,630
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [InterestRateSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsAssetsMember] | [ToBeAnnouncedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ForeignExchangeForwardMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ForeignExchangeOptionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [FutureMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [CreditDefaultSwapBuyingProtectionMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [InsuranceLinkedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(390)	(2,173)
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [TotalReturnSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(732)	(546)
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [InterestRateSwapMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
[FairValueInputsLevel3Member] | [DerivativeFinancialInstrumentsLiabilitiesMember] | [ToBeAnnouncedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
[FairValueInputsLevel3Member] | [OtherInvestedAssetsNotesAndLoanReceivablesAndNotesSecuritizationMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	47,781	34,902
[FairValueInputsLevel3Member] | [OtherInvestedAssetsAnnuitiesAndResidualsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	26,939	46,882
[FairValueInputsLevel3Member] | [PrivateEquitiesTotalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	21,878	1,404
[FairValueInputsLevel3Member] | [OtherInvestedAssetsFundsHeldDirectlyManagedMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	15,566	17,976
[FairValueInputsLevel3Member] | [RealEstateInvestmentMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel3Member] | [EnergyMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel3Member] | [FinanceMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	14,285	13,477
[FairValueInputsLevel3Member] | [ConsumerNoncyclicalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel3Member] | [CommunicationsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	2,143	0
[FairValueInputsLevel3Member] | [TechnologyMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	9,150	6,987
[FairValueInputsLevel3Member] | [IndustrialsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel3Member] | [ConsumerCyclicalMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel3Member] | [PublicUtilityEquitiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0
[FairValueInputsLevel3Member] | [InsuranceMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel3Member] | [OtherEquitiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	0	0
[FairValueInputsLevel3Member] | [MutualFundsAndExchangeTradedFundsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities, trading securities	7,674	7,264
[FairValueInputsLevel3Member] | [USTreasuryAndGovernmentMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
Funds held - directly managed	0	0
[FairValueInputsLevel3Member] | [USStatesAndPoliticalSubdivisionsMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	289,135	233,235
Funds held - directly managed	298	345
[FairValueInputsLevel3Member] | [NonUsSovereignGovernmentSupranationalAndGovernmentRelatedMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
Funds held - directly managed	0	0
[FairValueInputsLevel3Member] | [CorporateDebtSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	99,627	100,904
Funds held - directly managed	0	0
[FairValueInputsLevel3Member] | [AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	453,753	323,134
[FairValueInputsLevel3Member] | [ResidentialMortgageBackedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	0	0
[FairValueInputsLevel3Member] | [CommercialMortgageBackedSecuritiesMember]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, trading securities	$ 0	$ 0