XML 39 R28.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value (Details - Valuation Technique and Inputs) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Fair Value Inputs Assets Quantitative Information [Line Items]    
Fixed maturities 13,412,011us-gaap_TradingSecuritiesDebt 13,918,745us-gaap_TradingSecuritiesDebt
Equities 1,320,284us-gaap_TradingSecuritiesEquity 1,056,514us-gaap_TradingSecuritiesEquity
Other invested assets carried at fair value 95,115pre_OtherInvestedAssetsCarriedAtFairValue 111,476pre_OtherInvestedAssetsCarriedAtFairValue
Funds held directly managed investments carried at fair value 434,548pre_FundsHeldDirectlyManagedInvestmentsCarriedAtFairValue 472,593pre_FundsHeldDirectlyManagedInvestmentsCarriedAtFairValue
Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Fixed maturities 599,266us-gaap_TradingSecuritiesDebt
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599,646us-gaap_TradingSecuritiesDebt
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Equities 289,834us-gaap_TradingSecuritiesEquity
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40,134us-gaap_TradingSecuritiesEquity
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Other invested assets carried at fair value 126,523pre_OtherInvestedAssetsCarriedAtFairValue
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= us-gaap_FairValueInputsLevel3Member
116,074pre_OtherInvestedAssetsCarriedAtFairValue
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= us-gaap_FairValueInputsLevel3Member
Funds held directly managed investments carried at fair value 12,140pre_FundsHeldDirectlyManagedInvestmentsCarriedAtFairValue
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= us-gaap_FairValueInputsLevel3Member
13,530pre_FundsHeldDirectlyManagedInvestmentsCarriedAtFairValue
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= us-gaap_FairValueInputsLevel3Member
US states, territories and municipalities [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Fixed maturities 147,683us-gaap_TradingSecuritiesDebt
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149,728us-gaap_TradingSecuritiesDebt
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= pre_DiscountedCashFlowMember
US states, territories and municipalities [Member] | Minimum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 2.60%us-gaap_FairValueInputsEntityCreditRisk
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2.20%us-gaap_FairValueInputsEntityCreditRisk
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= pre_DiscountedCashFlowMember
US states, territories and municipalities [Member] | Maximum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 10.50%us-gaap_FairValueInputsEntityCreditRisk
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10.10%us-gaap_FairValueInputsEntityCreditRisk
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= pre_DiscountedCashFlowMember
US states, territories and municipalities [Member] | Weighted Average [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 6.00%us-gaap_FairValueInputsEntityCreditRisk
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4.60%us-gaap_FairValueInputsEntityCreditRisk
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= pre_DiscountedCashFlowMember
Asset-backed securities - other [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Fixed maturities 451,583us-gaap_TradingSecuritiesDebt
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449,918us-gaap_TradingSecuritiesDebt
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= pre_DiscountedCashFlowMember
Asset-backed securities - other [Member] | Minimum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 4.00%us-gaap_FairValueInputsEntityCreditRisk
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4.00%us-gaap_FairValueInputsEntityCreditRisk
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= pre_DiscountedCashFlowMember
Asset-backed securities - other [Member] | Maximum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 12.00%us-gaap_FairValueInputsEntityCreditRisk
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12.10%us-gaap_FairValueInputsEntityCreditRisk
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Asset-backed securities - other [Member] | Weighted Average [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 7.20%us-gaap_FairValueInputsEntityCreditRisk
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7.10%us-gaap_FairValueInputsEntityCreditRisk
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= pre_DiscountedCashFlowMember
Finance [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Equities 14,748us-gaap_TradingSecuritiesEquity
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14,561us-gaap_TradingSecuritiesEquity
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Finance [Member] | Profitability Analysis [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Equities 5,784us-gaap_TradingSecuritiesEquity
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5,792us-gaap_TradingSecuritiesEquity
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Finance [Member] | Minimum [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net income multiple 19.0pre_FairValueInputsNetIncomeMultiple
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19.0pre_FairValueInputsNetIncomeMultiple
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Tangible book value multiple 1.3pre_FairValueInputsTangibleBookValueMultiple
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1.3pre_FairValueInputsTangibleBookValueMultiple
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Liquidity discount 25.00%us-gaap_FairValueInputsDiscountForLackOfMarketability
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25.00%us-gaap_FairValueInputsDiscountForLackOfMarketability
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Comparable return 1.40%us-gaap_FairValueInputsComparabilityAdjustments
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7.30%us-gaap_FairValueInputsComparabilityAdjustments
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Finance [Member] | Minimum [Member] | Profitability Analysis [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Projected Return On Equity 14.00%pre_ProjectedReturnOnEquity
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14.00%pre_ProjectedReturnOnEquity
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Finance [Member] | Maximum [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net income multiple 19.0pre_FairValueInputsNetIncomeMultiple
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19.0pre_FairValueInputsNetIncomeMultiple
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Tangible book value multiple 1.3pre_FairValueInputsTangibleBookValueMultiple
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1.3pre_FairValueInputsTangibleBookValueMultiple
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Liquidity discount 25.00%us-gaap_FairValueInputsDiscountForLackOfMarketability
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25.00%us-gaap_FairValueInputsDiscountForLackOfMarketability
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Comparable return 1.40%us-gaap_FairValueInputsComparabilityAdjustments
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7.30%us-gaap_FairValueInputsComparabilityAdjustments
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Finance [Member] | Maximum [Member] | Profitability Analysis [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Projected Return On Equity 14.00%pre_ProjectedReturnOnEquity
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14.00%pre_ProjectedReturnOnEquity
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Finance [Member] | Weighted Average [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net income multiple 19.0pre_FairValueInputsNetIncomeMultiple
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19.0pre_FairValueInputsNetIncomeMultiple
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Comparable return 1.40%us-gaap_FairValueInputsComparabilityAdjustments
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7.30%us-gaap_FairValueInputsComparabilityAdjustments
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Finance [Member] | Weighted Average [Member] | Profitability Analysis [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Projected Return On Equity 14.00%pre_ProjectedReturnOnEquity
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Communications [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Equities 2,723us-gaap_TradingSecuritiesEquity
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2,640us-gaap_TradingSecuritiesEquity
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Communications [Member] | Minimum [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Adjusted earnings multiple 9.4us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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9.4us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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Comparable return 3.20%us-gaap_FairValueInputsComparabilityAdjustments
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= us-gaap_FairValueInputsLevel3Member
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= us-gaap_MinimumMember
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= pre_WeightedMarketComparablesMember
(10.60%)us-gaap_FairValueInputsComparabilityAdjustments
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= us-gaap_FairValueInputsLevel3Member
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= pre_WeightedMarketComparablesMember
Communications [Member] | Maximum [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Adjusted earnings multiple 9.4us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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= pre_CommunicationsMember
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9.4us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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= us-gaap_FairValueInputsLevel3Member
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
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= pre_WeightedMarketComparablesMember
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/ us-gaap_FairValueByAssetClassAxis
= pre_CommunicationsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_ValuationTechniqueAxis
= pre_WeightedMarketComparablesMember
(10.60%)us-gaap_FairValueInputsComparabilityAdjustments
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= pre_CommunicationsMember
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= us-gaap_FairValueInputsLevel3Member
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
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= pre_WeightedMarketComparablesMember
Communications [Member] | Weighted Average [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Adjusted earnings multiple 9.4us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
/ us-gaap_FairValueByAssetClassAxis
= pre_CommunicationsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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= us-gaap_WeightedAverageMember
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= pre_WeightedMarketComparablesMember
9.4us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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= pre_CommunicationsMember
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= us-gaap_FairValueInputsLevel3Member
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
/ us-gaap_ValuationTechniqueAxis
= pre_WeightedMarketComparablesMember
Comparable return 3.20%us-gaap_FairValueInputsComparabilityAdjustments
/ us-gaap_FairValueByAssetClassAxis
= pre_CommunicationsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
/ us-gaap_ValuationTechniqueAxis
= pre_WeightedMarketComparablesMember
(10.60%)us-gaap_FairValueInputsComparabilityAdjustments
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= us-gaap_FairValueInputsLevel3Member
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= us-gaap_WeightedAverageMember
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= pre_WeightedMarketComparablesMember
Technology [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Equities 8,602us-gaap_TradingSecuritiesEquity
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= pre_TechnologyMember
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= us-gaap_FairValueInputsLevel3Member
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8,555us-gaap_TradingSecuritiesEquity
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/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
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= pre_WeightedMarketComparablesMember
Technology [Member] | Minimum [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Adjusted earnings multiple 10.6us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
/ us-gaap_FairValueByAssetClassAxis
= pre_TechnologyMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
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= us-gaap_MinimumMember
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= pre_WeightedMarketComparablesMember
10.2us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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1.6us-gaap_FairValueInputsRevenueMultiple
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= pre_WeightedMarketComparablesMember
Technology [Member] | Maximum [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Adjusted earnings multiple 10.6us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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10.2us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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1.6us-gaap_FairValueInputsRevenueMultiple
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Technology [Member] | Weighted Average [Member] | Weighted market comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Adjusted earnings multiple 10.6us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
/ us-gaap_FairValueByAssetClassAxis
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10.2us-gaap_FairValueInputsEarningsBeforeInterestTaxesDepreciationAndAmortizationMultiple
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1.6us-gaap_FairValueInputsRevenueMultiple
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Total return swaps [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Other invested assets carried at fair value (1,057)pre_OtherInvestedAssetsCarriedAtFairValue
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(1,522)pre_OtherInvestedAssetsCarriedAtFairValue
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Total return swaps [Member] | Minimum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 3.80%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
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= us-gaap_FairValueInputsLevel3Member
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3.60%us-gaap_FairValueInputsEntityCreditRisk
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= us-gaap_FairValueInputsLevel3Member
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Total return swaps [Member] | Maximum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 19.90%us-gaap_FairValueInputsEntityCreditRisk
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= us-gaap_TotalReturnSwapMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
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= pre_DiscountedCashFlowMember
19.30%us-gaap_FairValueInputsEntityCreditRisk
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= us-gaap_FairValueInputsLevel3Member
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Total return swaps [Member] | Weighted Average [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 14.60%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_TotalReturnSwapMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
/ us-gaap_ValuationTechniqueAxis
= pre_DiscountedCashFlowMember
16.30%us-gaap_FairValueInputsEntityCreditRisk
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= us-gaap_TotalReturnSwapMember
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= us-gaap_FairValueInputsLevel3Member
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Notes and loan receivables [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Other invested assets carried at fair value 13,209pre_OtherInvestedAssetsCarriedAtFairValue
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= pre_OtherInvestedAssetsNotesAndLoanReceivablesMember
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= pre_DiscountedCashFlowMember
13,237pre_OtherInvestedAssetsCarriedAtFairValue
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Notes and loan receivables [Member] | Minimum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 17.50%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
= pre_OtherInvestedAssetsNotesAndLoanReceivablesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
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= us-gaap_MinimumMember
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= pre_DiscountedCashFlowMember
17.50%us-gaap_FairValueInputsEntityCreditRisk
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= pre_DiscountedCashFlowMember
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1.5us-gaap_FairValueInputsRevenueMultiple
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Notes and loan receivables [Member] | Maximum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 17.50%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
= pre_OtherInvestedAssetsNotesAndLoanReceivablesMember
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= us-gaap_FairValueInputsLevel3Member
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17.50%us-gaap_FairValueInputsEntityCreditRisk
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1.7us-gaap_FairValueInputsRevenueMultiple
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= pre_DiscountedCashFlowMember
Notes and loan receivables [Member] | Weighted Average [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 17.50%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
= pre_OtherInvestedAssetsNotesAndLoanReceivablesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_RangeAxis
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= pre_DiscountedCashFlowMember
17.50%us-gaap_FairValueInputsEntityCreditRisk
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= pre_OtherInvestedAssetsNotesAndLoanReceivablesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
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= pre_DiscountedCashFlowMember
Gross revenue/fair value 1.6us-gaap_FairValueInputsRevenueMultiple
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1.7us-gaap_FairValueInputsRevenueMultiple
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= pre_DiscountedCashFlowMember
Notes and Loans Receivable 2 [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Other invested assets carried at fair value 11,607pre_OtherInvestedAssetsCarriedAtFairValue
/ us-gaap_FairValueByAssetClassAxis
= pre_OtherInvestedAssetsNotesandLoansReceivable2Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_ValuationTechniqueAxis
= pre_DiscountedCashFlowMember
8,068pre_OtherInvestedAssetsCarriedAtFairValue
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= pre_DiscountedCashFlowMember
Notes and Loans Receivable 2 [Member] | Minimum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 6.10%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
= pre_OtherInvestedAssetsNotesandLoansReceivable2Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
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= us-gaap_MinimumMember
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= pre_DiscountedCashFlowMember
12.60%us-gaap_FairValueInputsEntityCreditRisk
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/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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Notes and Loans Receivable 2 [Member] | Maximum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 10.60%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
= pre_OtherInvestedAssetsNotesandLoansReceivable2Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
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= pre_DiscountedCashFlowMember
12.60%us-gaap_FairValueInputsEntityCreditRisk
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= us-gaap_FairValueInputsLevel3Member
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= pre_DiscountedCashFlowMember
Notes and Loans Receivable 2 [Member] | Weighted Average [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 9.10%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
= pre_OtherInvestedAssetsNotesandLoansReceivable2Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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12.60%us-gaap_FairValueInputsEntityCreditRisk
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Notes securitization [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Other invested assets carried at fair value 26,287pre_OtherInvestedAssetsCarriedAtFairValue
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/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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23,512pre_OtherInvestedAssetsCarriedAtFairValue
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Notes securitization [Member] | Minimum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 3.90%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
= pre_OtherInvestedAssetsNotesSecuritizationMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
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= pre_DiscountedCashFlowMember
3.50%us-gaap_FairValueInputsEntityCreditRisk
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Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 6.50%us-gaap_FairValueInputsEntityCreditRisk
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6.60%us-gaap_FairValueInputsEntityCreditRisk
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Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 6.40%us-gaap_FairValueInputsEntityCreditRisk
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6.40%us-gaap_FairValueInputsEntityCreditRisk
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Fair Value Inputs Assets Quantitative Information [Line Items]    
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13,243pre_OtherInvestedAssetsCarriedAtFairValue
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Annuities and residuals [Member] | Minimum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 5.20%us-gaap_FairValueInputsEntityCreditRisk
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4.90%us-gaap_FairValueInputsEntityCreditRisk
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0.00%us-gaap_FairValueInputsPrepaymentRate
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0.30%us-gaap_FairValueInputsProbabilityOfDefault
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Annuities and residuals [Member] | Maximum [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 9.10%us-gaap_FairValueInputsEntityCreditRisk
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9.60%us-gaap_FairValueInputsEntityCreditRisk
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15.00%us-gaap_FairValueInputsPrepaymentRate
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17.50%us-gaap_FairValueInputsProbabilityOfDefault
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Annuities and residuals [Member] | Weighted Average [Member] | Discounted cash flow [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Credit spreads 7.80%us-gaap_FairValueInputsEntityCreditRisk
/ us-gaap_FairValueByAssetClassAxis
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7.80%us-gaap_FairValueInputsEntityCreditRisk
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4.30%us-gaap_FairValueInputsPrepaymentRate
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6.30%us-gaap_FairValueInputsProbabilityOfDefault
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Private Equity-Direct [Member] | Discounted Cash Flow And Weighted Market Comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Other invested assets carried at fair value 9,035pre_OtherInvestedAssetsCarriedAtFairValue
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= pre_PrivateEquityDirectMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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8,536pre_OtherInvestedAssetsCarriedAtFairValue
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= us-gaap_FairValueInputsLevel3Member
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Private Equity-Direct [Member] | Minimum [Member] | Discounted Cash Flow And Weighted Market Comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net income multiple 9.2pre_FairValueInputsNetIncomeMultiple
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= us-gaap_FairValueInputsLevel3Member
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9.0pre_FairValueInputsNetIncomeMultiple
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Tangible book value multiple 2.0pre_FairValueInputsTangibleBookValueMultiple
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0.000pre_ValueOfIntangibleAssets
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Private Equity-Direct [Member] | Maximum [Member] | Discounted Cash Flow And Weighted Market Comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net income multiple 9.2pre_FairValueInputsNetIncomeMultiple
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9.0pre_FairValueInputsNetIncomeMultiple
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Tangible book value multiple 2.0pre_FairValueInputsTangibleBookValueMultiple
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2.0pre_FairValueInputsTangibleBookValueMultiple
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0.000pre_ValueOfIntangibleAssets
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Private Equity-Direct [Member] | Weighted Average [Member] | Discounted Cash Flow And Weighted Market Comparables [Member] | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net income multiple 9.2pre_FairValueInputsNetIncomeMultiple
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9.0pre_FairValueInputsNetIncomeMultiple
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2.0pre_FairValueInputsTangibleBookValueMultiple
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Private equity funds [Member] | Lag reported market value | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Other invested assets carried at fair value 23,676pre_OtherInvestedAssetsCarriedAtFairValue
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18,494pre_OtherInvestedAssetsCarriedAtFairValue
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Private equity funds [Member] | Minimum [Member] | Lag reported market value | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net asset value, as reported 100.00%pre_FairValueInputsLagReportedNetAssetValue
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100.00%pre_FairValueInputsLagReportedNetAssetValue
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= us-gaap_FairValueInputsLevel3Member
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(7.60%)pre_FairValueInputsAdjustedLagReportedNetAssetValue
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Private equity funds [Member] | Maximum [Member] | Lag reported market value | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net asset value, as reported 100.00%pre_FairValueInputsLagReportedNetAssetValue
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11.00%pre_FairValueInputsAdjustedLagReportedNetAssetValue
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Private equity funds [Member] | Weighted Average [Member] | Lag reported market value | Significant unobservable inputs (Level 3) [Member]    
Fair Value Inputs Assets Quantitative Information [Line Items]    
Net asset value, as reported 100.00%pre_FairValueInputsLagReportedNetAssetValue
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100.00%pre_FairValueInputsLagReportedNetAssetValue
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Fair Value Inputs Assets Quantitative Information [Line Items]    
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Fair Value Inputs Assets Quantitative Information [Line Items]    
Effective Yield 5.80%pre_EffectiveYield
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Fair Value Inputs Assets Quantitative Information [Line Items]    
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Fair Value Inputs Assets Quantitative Information [Line Items]    
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Fair Value Inputs Assets Quantitative Information [Line Items]    
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Fair Value Inputs Assets Quantitative Information [Line Items]    
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Fair Value Inputs Assets Quantitative Information [Line Items]    
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Fair Value Inputs Assets Quantitative Information [Line Items]    
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