Unpaid Losses and Loss Expenses and Policy Benefits for Life and Annuity Contracts (Details - Other Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Prior Year Development [Line Items]
Total net Non-life prior year loss development	$ 530,457,000	$ 477,883,000	$ 485,809,000
Liability For Asbestos And Environmental Claims [Line Items]
Net liability for asbestos and environmental claims	195,000,000	214,000,000
Gross liability for asbestos and environmental claims	203,000,000	222,000,000
Liability For Future Policy Benefits [Line Items]
Development from prior accident years	1,000,000	(12,000,000)	15,000,000
Interest rate assumptions
Low end interest rate assumption	1.00%	1.00%
High end interest rate assumption	7.00%	6.00%
[LongevityMember]
Liability For Future Policy Benefits [Line Items]
Development from prior accident years		(23,000,000)
[GmdbMember]
Liability For Future Policy Benefits [Line Items]
Development from prior accident years	5,000,000	17,000,000	15,000,000
[MortalityMember]
Liability For Future Policy Benefits [Line Items]
Development from prior accident years	6,000,000
[AsbestosLiabilitiesOfParisReMember]
Liability For Asbestos And Environmental Claims [Line Items]
Gross liability for asbestos and environmental claims	127,000,000	144,000,000
[AsbestosLiabilitiesOfPartnerReSaAndPartnerReUsMember]
Liability For Asbestos And Environmental Claims [Line Items]
Gross liability for asbestos and environmental claims	76,000,000	78,000,000
[NorthAmericaMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development	189,180,000	165,780,000	177,571,000
[NorthAmericaMember] | [MotorMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development		(8,000,000)
[NorthAmericaMember] | [MultilineMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development			(8,000,000)
[NorthAmericaMember] | [CreditsuretyAndMotorCombinedMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development	(11,000,000)
[GlobalNonUsPcMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development	115,995,000	97,539,000	151,456,000
[GlobalNonUsSpecialtyMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development	128,975,000	170,931,000	107,632,000
[GlobalNonUsSpecialtyMember] | [SpecialtyCasualtyMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development		(37,000,000)
[GlobalNonUsSpecialtyMember] | [EnergyAndEngineeringCombinedMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development	(13,000,000)
[CatastropheSegmentMember]
Prior Year Development [Line Items]
Total net Non-life prior year loss development	$ 96,307,000	$ 43,633,000	$ 49,150,000