Name:	rnr_TradingSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCostBasis
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the fair value of debt securities which are expected to mature after five through ten years of the balance sheet date and are categorized as trading securities.

No definition available.

Name:	rnr_TradingSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents debt securities, at cost, net of adjustments including accretion, amortization and collection of cash, if any, which are expected to mature within one year of the balance sheet date and are categorized as trading securities.

No definition available.

Name:	rnr_TradingSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCostBasis
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the fair value of debt securities which are expected to mature after one through five years of the balance sheet date and are categorized as trading securities.

No definition available.

Name:	rnr_TradingSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents debt securities, at cost, net of adjustments including accretion, amortization and collection of cash, if any, which are expected to mature after ten years of the balance sheet date and are categorized as trading securities.

No definition available.

Name:	rnr_TradingSecuritiesDebtMaturitiesAfterTenYearsAmortizedCostBasis
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the fair value of debt securities which are expected to mature after ten years of the balance sheet date and are categorized as trading securities.

No definition available.

Name:	rnr_TradingSecuritiesDebtMaturitiesAfterTenYearsFairValue
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

No definition available.

Name:	rnr_TradingSecuritiesDebtMaturitiesWithinOneYearAmortizedCostBasis
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and are categorized as trading securities.

No definition available.

Name:	rnr_TradingSecuritiesDebtMaturitiesWithinOneYearFairValue
Namespace Prefix:	rnr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiCostAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

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

Amortized cost of investments in debt securities classified as trading.

No definition available.