<DefinitionAndReference>
  <Element Id="us-gaap_Assets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_Investments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockDividendsPerShareDeclared">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TradingSecuritiesDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_OtherNetAssets">
    <definition>Other invested assets and liabilities carried at cost, which are related to the underlying business related to the funds held - directly managed account.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PremiumsWrittenNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ScheduleOfDerivativeInstrumentsGainLossInStatementOfOperationsTableTextBlock">
    <definition>A table that identifies and provides pertinent information about a derivative or group of derivatives on a disaggregated basis and describes the location and amount of gains and losses reported in the statement of operations.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInDeferredPolicyAcquisitionCosts">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IntangibleAssetsNetExcludingGoodwill">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CashAndCashEquivalentsAtCarryingValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PreferredStockSharesOutstanding">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TreasuryStockShares">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLossIncludedInInvestmentIncome">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherIncome">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxesPaid">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ChangeInUnearnedPremiums">
    <definition>Change during the period in the unearned gross premiums written (direct and assumed) and ceded premiums written.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_WeightedAverageNumberOfCommonSharesAndCommonShareEquivalentsOutstandingIncludingPotentiallyDilutiveSecurities">
    <definition>The weighted average number of common and common share equivalents outstanding, including potentially dilutive securities which were not taken into account in the computation of diluted earnings per share because to do so would have been anti-dilutive.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_PurchasesOfEquities">
    <definition>Includes purchases of equities designated as trading under the fair value option or equities categorized as available-for-sale or held-to-maturity which the Company held as of the date it opted to account for such securities at fair value.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InterestExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsForProceedsFromOtherInvestingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_SalesOfEquities">
    <definition>Includes sales of equities designated as trading under the fair value option or equities categorized as available-for-sale or held-to-maturity which the Company held as of the date it opted to account for such securities at fair value.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FixedMaturitiesTradingSecuritiesAmortizedCost">
    <definition>Fixed maturities, trading securities, amortized cost</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_OtherOperatingExpenseRatioPercentage">
    <definition>Other operating expense ratio is obtained by dividing other operating expenses by net premiums earned</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_DocumentPeriodEndDate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_EquitiesTradingSecuritiesCost">
    <definition>Equities, trading securities, cost</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_SalesOfFixedMaturities">
    <definition>Includes sales of fixed maturities designated as trading under the fair value option or fixed maturities categorized as available-for-sale or held-to-maturity which the Company held as of the date it opted to account for such securities at fair value.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_JuniorSubordinatedNotes">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ReinsuranceRecoverableOnPaidAndUnpaidLossesNetOfCededPremiumsPayable">
    <definition>The net change during the reporting period in reinsurance recoverable on paid and unpaid losses, net of ceded premiums payable</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueDisclosuresTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityCurrentReportingStatus">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityFilerCategory">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DividendsPreferredStock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales">
    <definition>Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_OtherAccumulatedComprehensiveIncomeLossNetOfTax">
    <definition>This element represents Other Accumulated Comprehensive Income (Loss), Net of Tax. Includes cumulative gains (losses) on qualifying hedges and minimum pension liability, but excludes currency translation adjustment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LiabilityForFuturePolicyBenefits">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_NetTaxLiabilities">
    <definition>The cumulative amount of tax-paying jurisdictions in a net liability position as of the balance sheet date arising from temporary differences between accounting income in accordance with generally accepted accounting principles and tax-basis income that will result in future taxable income exceeding future accounting income. Includes current taxes payable.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_InvestmentsNotCarriedAtFairValue">
    <definition>Investments that the Company did not measure at fair value on the balance sheet date, which primarily relate to the company's investments that are accounted for using the cost method of accounting, equity method of accounting or investment company accounting.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ReinsuranceRecoverables">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TreasuryStockValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetIncomeLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PolicyholderBenefitsAndClaimsIncurredNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_SeriesCPreferenceSharesAggregateLiquidationValue">
    <definition>In the event of liquidation of the Company, the holders of outstanding preferred shares would have preference over the common shareholders and would receive a distribution of $25.00 per share, or an aggregate value of $290 million, plus accrued and unpaid dividends.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="invest_DerivativeNotionalAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InvestmentsFairValueDisclosure">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PreferredStockSharesIssued">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ReinsurancePayable">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FundsHeldDirectlyManagedInvestmentsCarriedAtFairValue">
    <definition>Carrying value of those investments held in the segregated investment portfolio underlying the funds held - directly managed account that are carried at fair value, comprised of fixed maturities, short-term investments and certain other invested assets. All changes in the fair value are recorded in net realized and unrealized investment gains and losses in the Consolidated Statement of Operations.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PremiumsReceivableAtCarryingValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EarningsPerShareTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_AllocatedUnderwritingResult">
    <definition>This element is defined as net premiums earned, other income or loss and allocated net investment income less life policy benefits, acquisition costs and other operating expenses for Life segment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_DocumentFiscalYearFocus">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_Revenues">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_OtherInvestedAssetsCarriedAtFairValue">
    <definition>Other invested assets carried at fair value.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetCashProvidedByUsedInOperatingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ChangeInUnrealizedGainLossOnFinancialInstrumentsTableTextBlock">
    <definition>A table that provides a breakdown of the change in the unrealized gain/loss of financial instruments subject to the fair value option, by major category of investment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccruedInvestmentIncomeReceivable">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_AcquisitionRatioPercentage">
    <definition>The acquisition ratio is obtained by dividing acquisition costs by net premiums earned.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_StockIssuedDuringPeriodValueNewIssues">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DepositContractsLiabilities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_CombinedRatioPercentage">
    <definition>The combined ratio is defined as the sum of the technical ratio and the other operating expense ratio.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_TechnicalRatioPercentage">
    <definition>Technical ratio is defined as the sum of the loss ratio and the acquisition ratio.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock">
    <definition>This element aggregates basis of presentation, or accounting, and significant accounting policies into a single text block.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_RedemptionsOfFixedMaturities">
    <definition>Includes redemptions of fixed maturities designated as trading under the fair value option or fixed maturities categorized as available-for-sale or held-to-maturity which the Company held as of the date it opted to account for such securities at fair value.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TreasuryStockValueAcquiredCostMethod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsToAcquireShortTermInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LiabilitiesAndStockholdersEquity">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockParOrStatedValuePerShare">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NatureOfOperations">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_Goodwill">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ShortTermInvestmentsTradingSecuritiesAtFairValue">
    <definition>This item represents short-term investments that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for short-term investments formerly categorized as available-for-sale or held-to-maturity which the entity held as of the date it opted to account for such securities at fair value. Such financial instruments that are held as of the reporting date are measured at fair value with unrealized holding gains and losses (the difference between fair value and the previously reported carrying amount) included in earnings</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_CurrentFiscalYearEndDate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ChangeInOtherAccumulatedComprehensiveIncomeLossNetOfTax">
    <definition>This element represents the change in other comprehensive income (loss), net of tax, for the period attributable to the parent entity. Includes gains (losses) on qualifying hedges, minimum pension liability, other comprehensive income on equity investments but excludes currency translation adjustment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueOptionChangesInFairValueGainLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_OtherAccumulatedComprehensiveIncomeLossTax">
    <definition>Tax effect on Other Accumulated Comprehensive Income (Loss), including cumulative gains (losses) on qualifying hedges and minimum pension liability, but excluding currency translation adjustment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_LossRatioPercentage">
    <definition>The loss ratio is obtained by dividing losses and loss expenses by net premiums earned.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeFairValueOfDerivativeNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_UnderwritingResult">
    <definition>Underwriting result is defined as the technical result net of other operating income and expenses.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_UnpaidLossesAndLossExpensesIncludingLifePolicyBenefits">
    <definition>The net change during the reporting period of unpaid losses and loss expenses and policy benefits for life and annuity contracts.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_PurchasesOfFixedMaturities">
    <definition>Includes purchases of fixed maturities designated as trading under the fair value option or fixed maturities categorized as available-for-sale or held-to-maturity which the Company held as of the date it opted to account for such securities at fair value.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ReinsuranceBalancesNet">
    <definition>The net change during the reporting period in the amounts due to or from other insurance companies when the reporting entity has assumed the risk on these policies. Includes changes in balances receivable and payable based on reports received from ceding companies, supplemented by the Company's estimates of premiums receivable and payable and other net receivable reinsurance balances.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PreferredStockParOrStatedValuePerShare">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PreferredStockValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityCentralIndexKey">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_NetTaxAssets">
    <definition>The aggregate tax effects of tax-paying jurisdictions in a net asset position as of the balance sheet date of all future tax deductions arising from temporary differences between tax basis and generally accepted accounting principles basis recognition of assets, liabilities, revenues and expenses, which can only be deducted for tax purposes when permitted under enacted tax laws; net of deducting the allocated valuation allowance, if any, to reduce such amount to net realizable value. Current tax receivables balances are also included in this amount.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FinancingReceivable">
    <definition>The amount of the recorded investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, accounts receivable (with terms exceeding one year), notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SeniorNotes">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EarningsPerShareDiluted">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_AmendmentFlag">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BenefitsLossesAndExpenses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_Liabilities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SegmentReportingDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ShortTermInvestmentsTradingSecuritiesAmortizedCost">
    <definition>Short-term investments, trading securities, amortized cost</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TradingSecuritiesEquity">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_CashAndCashEquivalentsFundsHeldDirectlyManaged">
    <definition>Represents the amount of cash and cash equivalents held in the portfolio underlying the funds held - directly managed account.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_ScheduleOfNetIncomePerShareTableTextBlock">
    <definition>Tabular disclosure of an entity's basic and diluted earnings per share calculations, including the disclosure of the numerators and denominators used in the calculations, including the effect that has been given to preferred dividends.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DividendsCommonStock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InterestPaid">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_DocumentFiscalPeriodFocus">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ComprehensiveIncomeNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InvestmentIncomeNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsForRepurchaseOfCommonStock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeLossFromEquityMethodInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FundsHeldUnderReinsuranceAgreementsAsset">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_NetTaxAssetsAndLiabilities">
    <definition>The net change during the reporting period of all current and deferred tax assets and liabilities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnearnedPremiums">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueByBalanceSheetGroupingTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_DocumentType">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UseOfEstimates">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsOfOrdinaryDividends">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DepositContractsAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxExpenseBenefit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherExpenses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FundsHeldDirectlyManaged">
    <definition>Carrying value of segregated investment portfolio underlying the funds held - directly managed account comprised of fixed maturities, short-term investments, cash and cash equivalents, other assets and liabilities and accrued investment income. Substantially all of the fixed maturities, short-term investments and certain other invested assets in the segregated portfolio underlying the funds held-directly managed account are carried at fair value and accordingly all changes in the fair value are recorded in net realized and unrealized investment gains and losses in the statement of operations.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases">
    <definition>Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_SeriesDPreferenceSharesAggregateLiquidationValue">
    <definition>In the event of liquidation of the Company, the holders of outstanding preferred shares would have preference over the common shareholders and would receive a distribution of $25.00 per share, or an aggregate value of $230 million, plus accrued and unpaid dividends.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3">
    <definition>Transfers out of assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredPolicyAcquisitionCosts">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FundsHeldByReinsuredCompaniesAndFundsHeldDirectlyManaged">
    <definition>The net change during the reporting period in the balances of both Funds held by reinsured companies and Funds held - directly managed.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3">
    <definition>Transfers into assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BasisOfAccounting">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetCashProvidedByUsedInFinancingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInUnearnedPremiums">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockSharesIssued">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GrossProfit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PremiumsEarnedNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_AccruedInvestmentIncomeFundsHeldDirectlyManaged">
    <definition>Interest, dividends, rents, ancillary and other revenues earned but not yet received on investments held in the portfolio underlying the funds held - directly managed account.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromIssuanceOrSaleOfEquity">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetCashProvidedByUsedInInvestingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityRegistrantName">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromSaleOfShortTermInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AmortizationOfIntangibleAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GainLossOnInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityWellKnownSeasonedIssuer">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RetainedEarningsAccumulatedDeficit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityVoluntaryFilers">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AssumedPremiumsWritten">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AdditionalPaidInCapital">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EarningsPerShareBasic">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityCommonStockSharesOutstanding">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_LossesAndLossExpensesAndLifePolicyBenefitsSegmentDisclosure">
    <definition>Provision for benefits, claims and claims settlement expenses incurred during the period net of the effects of contracts assumed and ceded, by segment and subsegment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="pre_FundsHeldDirectlyManagedCost">
    <definition>Funds held - directly managed, cost</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
</DefinitionAndReference>
