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Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	$ 4,783,570us-gaap_MarketableSecuritiesFixedMaturities	$ 4,843,277us-gaap_MarketableSecuritiesFixedMaturities
Short-term investments	1,013,222us-gaap_OtherShortTermInvestments	1,044,779us-gaap_OtherShortTermInvestments
Equity investments trading	322,098us-gaap_TradingSecuritiesEquity	254,776us-gaap_TradingSecuritiesEquity
Other investments	504,147us-gaap_OtherInvestments	573,264us-gaap_OtherInvestments
Total other assets and (liabilities)	(13,908)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis	(8,233)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis
Total assets and liabilities measured on recurring basis	6,609,129rnr_TotalAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasis	6,707,863rnr_TotalAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasis
Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	1,671,471us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	1,352,413us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Short-term investments	0us-gaap_OtherShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	0us-gaap_OtherShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Equity investments trading	322,098us-gaap_TradingSecuritiesEquity / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	254,776us-gaap_TradingSecuritiesEquity / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Total other assets and (liabilities)	(569)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	823rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Total assets and liabilities measured on recurring basis	1,993,000rnr_TotalAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	1,608,012rnr_TotalAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	3,096,439us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	3,463,284us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Short-term investments	1,013,222us-gaap_OtherShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	1,044,779us-gaap_OtherShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Equity investments trading	0us-gaap_TradingSecuritiesEquity / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	0us-gaap_TradingSecuritiesEquity / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Other investments	200,329us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	229,016us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Total other assets and (liabilities)	(4,405)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	(6,566)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Total assets and liabilities measured on recurring basis	4,305,585rnr_TotalAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	4,730,513rnr_TotalAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	15,660us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	27,580us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Short-term investments	0us-gaap_OtherShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	0us-gaap_OtherShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Equity investments trading	0us-gaap_TradingSecuritiesEquity / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	0us-gaap_TradingSecuritiesEquity / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Other investments	303,818us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	344,248us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Total other assets and (liabilities)	(8,934)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	(2,490)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Total assets and liabilities measured on recurring basis	310,544rnr_TotalAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	369,338rnr_TotalAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
U.S. treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	1,671,471us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_USTreasurySecuritiesMember	1,352,413us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_USTreasurySecuritiesMember
U.S. treasuries | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	1,671,471us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_USTreasurySecuritiesMember	1,352,413us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_USTreasurySecuritiesMember
U.S. treasuries | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_USTreasurySecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_USTreasurySecuritiesMember
U.S. treasuries | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_USTreasurySecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_USTreasurySecuritiesMember
Agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	96,208us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AgencySecuritiesMember	186,050us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AgencySecuritiesMember
Agencies | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AgencySecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AgencySecuritiesMember
Agencies | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	96,208us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AgencySecuritiesMember	186,050us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AgencySecuritiesMember
Agencies | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AgencySecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AgencySecuritiesMember
Non-U.S. government (Sovereign Debt)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	280,651us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember	334,580us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember
Non-U.S. government (Sovereign Debt) | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember
Non-U.S. government (Sovereign Debt) | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	280,651us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember	334,580us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember
Non-U.S. government (Sovereign Debt) | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember
Non-U.S. government-backed corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	146,467us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = rnr_NonUSGovernmentBackedCorporateDebtSecuritiesMember	237,479us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = rnr_NonUSGovernmentBackedCorporateDebtSecuritiesMember
Non-U.S. government-backed corporate | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_NonUSGovernmentBackedCorporateDebtSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_NonUSGovernmentBackedCorporateDebtSecuritiesMember
Non-U.S. government-backed corporate | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	146,467us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_NonUSGovernmentBackedCorporateDebtSecuritiesMember	237,479us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_NonUSGovernmentBackedCorporateDebtSecuritiesMember
Non-U.S. government-backed corporate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_NonUSGovernmentBackedCorporateDebtSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_NonUSGovernmentBackedCorporateDebtSecuritiesMember
Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	1,610,442us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CorporateDebtSecuritiesMember	1,803,415us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CorporateDebtSecuritiesMember
Corporate | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CorporateDebtSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CorporateDebtSecuritiesMember
Corporate | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	1,594,782us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CorporateDebtSecuritiesMember	1,775,835us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CorporateDebtSecuritiesMember
Corporate | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	15,660us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CorporateDebtSecuritiesMember	27,580us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CorporateDebtSecuritiesMember
Agency mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	316,620us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember	341,908us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Agency mortgage-backed | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Agency mortgage-backed | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	316,620us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember	341,908us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Agency mortgage-backed | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Non-agency mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	253,050us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember	257,938us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Non-agency mortgage-backed | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Non-agency mortgage-backed | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	253,050us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember	257,938us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Non-agency mortgage-backed | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	381,051us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CommercialMortgageBackedSecuritiesMember	314,236us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CommercialMortgageBackedSecuritiesMember
Commercial mortgage-backed | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CommercialMortgageBackedSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CommercialMortgageBackedSecuritiesMember
Commercial mortgage-backed | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	381,051us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CommercialMortgageBackedSecuritiesMember	314,236us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CommercialMortgageBackedSecuritiesMember
Commercial mortgage-backed | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CommercialMortgageBackedSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CommercialMortgageBackedSecuritiesMember
Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	27,610us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AssetBackedSecuritiesMember	15,258us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AssetBackedSecuritiesMember
Asset-backed | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AssetBackedSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AssetBackedSecuritiesMember
Asset-backed | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	27,610us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AssetBackedSecuritiesMember	15,258us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AssetBackedSecuritiesMember
Asset-backed | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity investments	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AssetBackedSecuritiesMember	0us-gaap_MarketableSecuritiesFixedMaturities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_AssetBackedSecuritiesMember
Private equity partnerships
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	281,932us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_PrivateEquityFundsMember	322,391us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_PrivateEquityFundsMember
Private equity partnerships | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_PrivateEquityFundsMember	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_PrivateEquityFundsMember
Private equity partnerships | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_PrivateEquityFundsMember	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_PrivateEquityFundsMember
Private equity partnerships | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	281,932us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_PrivateEquityFundsMember	322,391us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_PrivateEquityFundsMember
Catastrophe bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	200,329us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = rnr_CatastropheBondsMember	229,016us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = rnr_CatastropheBondsMember
Catastrophe bonds | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_CatastropheBondsMember	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_CatastropheBondsMember
Catastrophe bonds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	200,329us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_CatastropheBondsMember	229,016us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_CatastropheBondsMember
Catastrophe bonds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_CatastropheBondsMember	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_CatastropheBondsMember
Senior secured bank loan funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	19,316us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = rnr_SeniorSecuredBankLoanFundsMember	18,048us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = rnr_SeniorSecuredBankLoanFundsMember
Senior secured bank loan funds | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_SeniorSecuredBankLoanFundsMember	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_SeniorSecuredBankLoanFundsMember
Senior secured bank loan funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_SeniorSecuredBankLoanFundsMember	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_SeniorSecuredBankLoanFundsMember
Senior secured bank loan funds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	19,316us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_SeniorSecuredBankLoanFundsMember	18,048us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_SeniorSecuredBankLoanFundsMember
Hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	2,570us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_HedgeFundsMember	3,809us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_HedgeFundsMember
Hedge funds | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_HedgeFundsMember	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_HedgeFundsMember
Hedge funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_HedgeFundsMember	0us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_HedgeFundsMember
Hedge funds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	2,570us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_HedgeFundsMember	3,809us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_HedgeFundsMember
Assumed and ceded reinsurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	(8,744)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByMeasurementBasisAxis = rnr_AssumedAndCededReInsuranceContractsMember
Assumed and ceded reinsurance contracts | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	0rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_AssumedAndCededReInsuranceContractsMember
Assumed and ceded reinsurance contracts | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	0rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_AssumedAndCededReInsuranceContractsMember
Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	6,345rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByMeasurementBasisAxis = rnr_DerivativesAssetsLiabilitiesMember	4,758rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByMeasurementBasisAxis = rnr_DerivativesAssetsLiabilitiesMember
Derivatives | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	(569)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_DerivativesAssetsLiabilitiesMember	823rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_DerivativesAssetsLiabilitiesMember
Derivatives | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	7,104rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_DerivativesAssetsLiabilitiesMember	6,425rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_DerivativesAssetsLiabilitiesMember
Derivatives | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	(190)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_DerivativesAssetsLiabilitiesMember	(2,490)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_DerivativesAssetsLiabilitiesMember
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	(11,509)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByMeasurementBasisAxis = rnr_OtherItemsMember	(12,991)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByMeasurementBasisAxis = rnr_OtherItemsMember
Other | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	0rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_OtherItemsMember	0rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_OtherItemsMember
Other | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other assets and (liabilities)	(11,509)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_OtherItemsMember	(12,991)rnr_OtherAssetsAndliabilitiesMeasuredonRecurringBasis / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementBasisAxis = rnr_OtherItemsMember
Other | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
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