No definition available.

Name:	rnr_FairValueInputsBondPrice
Namespace Prefix:	rnr_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Fair Value Inputs, Contract Period

No definition available.

Name:	rnr_FairValueInputsContractPeriod
Namespace Prefix:	rnr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Fair Value Inputs, Credit Spread Over Risk-Free Rate

No definition available.

Name:	rnr_FairValueInputsCreditSpreadOverRiskFreeRate
Namespace Prefix:	rnr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Estimated percentage return for the period on fair value at beginning of period.

No definition available.

Name:	rnr_FairValueInputsEstimatedPerformance
Namespace Prefix:	rnr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Fair Value Inputs, Expected Loss Ratio

No definition available.

Name:	rnr_FairValueInputsExpectedLossRatio
Namespace Prefix:	rnr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Fair Value Inputs, Liquidity Premium

No definition available.

Name:	rnr_FairValueInputsLiquidityPremium
Namespace Prefix:	rnr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Fair Value Inputs, Net Acquisition Expense Ratio

No definition available.

Name:	rnr_FairValueInputsNetAcquisitionExpenseRatio
Namespace Prefix:	rnr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Fair Value Inputs, Net Undiscounted Cash Flows

No definition available.

Name:	rnr_FairValueInputsNetUndiscountedCashFlows
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a recurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

Name:	us-gaap_AssetsFairValueDisclosureRecurring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

Name:	us-gaap_FairValueAssumptionsExpectedDividendRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Risk-free interest rate assumption used in valuing an instrument.

Name:	us-gaap_FairValueAssumptionsRiskFreeInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Adjustment to the discount rate used to measure fair value for lack of ability to convert business interests into cash quickly.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

Name:	us-gaap_FairValueInputsDiscountForLackOfMarketability
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

Name:	us-gaap_FairValueInputsDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Risk associated with risk of default, credit spread risk and downgrade risk, expressed as a percentage, used as an input to measure fair value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

Name:	us-gaap_FairValueInputsEntityCreditRisk
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Aggregation of the liabilities reported on the balance sheet measured at fair value on a recurring basis by the entity.

No definition available.

Name:	us-gaap_LiabilitiesFairValueDisclosureRecurring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-Subparagraph (a),(b),(c)

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

Name:	us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	us-gaap_FairValueByAssetClassAxis=rnr_AssumedandCededReInsuranceContractsGroupOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=rnr_AssumedandCededReInsuranceContractsGroupThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=rnr_AssumedandCededReInsuranceContractsGroupTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=rnr_AssumedAndCededReInsuranceContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=rnr_SeniorSecuredBankLoanFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=rnr_WeatherContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_FixedMaturitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_HedgeFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_OtherInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_PrivateEquityFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: