v2.3.0.15

Fair Value Measurements (Narrative) (Details) (USD $) | 9 Months Ended | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended |  |  |  |  | 48 Months Ended |  |  |  |  | 3 Months Ended |  |  |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 30, 2011 | Sep. 30, 2010 | Sep. 30, 2010 Other Investments [Member] | Sep. 30, 2011 Other Investments [Member] | Sep. 30, 2010 Other Investments [Member] | Sep. 30, 2011 Other Investments [Member] | Sep. 30, 2011 Reinsurance Contracts Accounted For At Fair Value [Member] | Sep. 30, 2010 Reinsurance Contracts Accounted For At Fair Value [Member] | Sep. 30, 2011 Reinsurance Contracts Accounted For At Fair Value [Member] | Sep. 30, 2010 Reinsurance Contracts Accounted For At Fair Value [Member] | Sep. 30, 2011 Other Assets and Liabilities [Member] | Sep. 30, 2010 Other Assets and Liabilities [Member] | Sep. 30, 2011 Other Assets and Liabilities [Member] | Sep. 30, 2010 Other Assets and Liabilities [Member] | Sep. 30, 2011 Reinsurance Contract Liabilities Accounted For At Fair Value [Member] | Dec. 31, 2010 Reinsurance Contract Liabilities Accounted For At Fair Value [Member] | Sep. 30, 2011 Reinsurance Contract Assets Accounted For At Fair Value [Member] | Dec. 31, 2010 Reinsurance Contract Assets Accounted For At Fair Value [Member] | Dec. 31, 2014 5.875% Senior Notes Due February 15, 2013 [Member] | Feb. 15, 2013 5.875% Senior Notes Due February 15, 2013 [Member] | Sep. 30, 2011 5.875% Senior Notes Due February 15, 2013 [Member] | Dec. 31, 2010 5.875% Senior Notes Due February 15, 2013 [Member] | Jan. 03, 2003 5.875% Senior Notes Due February 15, 2013 [Member] | Mar. 31, 2010 5.75% Senior Notes Due March 15, 2020 [Member] | Sep. 30, 2011 5.75% Senior Notes Due March 15, 2020 [Member] | Dec. 31, 2010 5.75% Senior Notes Due March 15, 2020 [Member] | Sep. 30, 2011 Senior Secured Bank Loan Funds [Member] | Sep. 30, 2011 Corporate [Member] | Sep. 30, 2011 U.S. Treasuries [Member] | Sep. 30, 2011 Non-U.S. Fixed Income Funds [Member] | Sep. 30, 2011 Hedge Funds [Member] | Sep. 30, 2011 Agencies [Member] | Sep. 30, 2011 FDIC Guaranteed Corporate [Member] | Sep. 30, 2011 Non-U.S. Government Backed-Corporate [Member] | Sep. 30, 2011 Non Agency Prime Residential Mortgage Backed Securities [Member] years | Sep. 30, 2011 AltA Non Agency Mortgage Backed Securities [Member] years | Sep. 30, 2011 Agency Mortgage-Backed [Member] years | Sep. 30, 2011 Commercial Mortgage-Backed [Member] years | Sep. 30, 2011 Asset-Backed [Member] years | Sep. 30, 2011 Non-U.S. Government (Sovereign Debt) [Member] | Sep. 30, 2011 Other Secured Assets [Member] | Sep. 30, 2010 Other Secured Assets [Member] | Sep. 30, 2011 Other Secured Assets [Member] | Sep. 30, 2010 Other Secured Assets [Member]
Weighted average effective yield |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.60% | 0.90% |  |  | 0.50% | 0.40% | 1.20% | 7.40% | 8.80% | 1.80% | 3.50% | 1.00% | 1.60% |  |  |  |
Debt instrument maturity date |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | February 15, 2013 |  |  |  |  | March 15, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Weighted average life of fixed maturity investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.0 | 3.8 | 2.8 | 4.1 | 1.2 |  |  |  |  |
Investments redeemable in part, on a monthly basis, or in whole over a three month period |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 231,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Investment in closed end fund |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 12,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Investments, fair value |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100,000 |  | 4,500,000 | 1,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Hedge fund side pocket investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on contracts |  |  |  |  |  |  | 2,700,000 | (800,000) | 39,900,000 | 3,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unrealized gain (loss) on contracts |  |  |  |  |  |  |  |  |  |  | 45,500,000 | 600,000 | 2,200,000 | 1,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior notes interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.875% |  |  |  | 5.75% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair value of Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 102,900,000 | 105,900,000 |  |  | 256,300,000 | 252,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100,000,000 | 250,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net unrealized gains (losses) related to changes in fair value of secured assets recorded in other income (losses) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 300,000 | 100,000 | 100,000
Investments redeemable on bi-monthly basis |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 29,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net unrealized gains included in other income (loss) | $ 16,018,000 | $ 21,005,000 | $ 21,000,000 | $ 42,900,000 | $ 15,300,000 | $ 9,200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition This item represents the weighted average life in years of the debt securities. + Details
Name: | rnr_DebtSecuritiesWeightedAverageLife
Namespace Prefix: | rnr
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of reinsurance contracts accounted for at fair value, held at each balance sheet date and included in earnings for the period. + Details
Name: | rnr_GainsLossesOnReinsuranceContractsAccountedForAtFairValue
Namespace Prefix: | rnr
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This item represents 'side pocket' investments which are not redeemable at the option of the shareholder. + Details
Name: | rnr_HedgeFundSidePocketInvestments
Namespace Prefix: | rnr
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents senior secured bank loan funds in a closed end fund, which the Company has no right to redeem. + Details
Name: | rnr_InvestmentInClosedEndFund
Namespace Prefix: | rnr
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the fair value of investments redeemable in part, on a monthly basis, or in whole over a three month period. + Details
Name: | rnr_InvestmentsRedeemableInPartMonthlyInTotalOverThreeMonths
Namespace Prefix: | rnr
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the fair value of investments redeemable, in whole or in part, on a bi-monthly basis. + Details
Name: | rnr_InvestmentsRedeemableOnBiMonthlyBasis
Namespace Prefix: | rnr
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Net unrealized gains related to changes in fair value of other assets and liabilities recorded in other income. + Details
Name: | rnr_NetUnrealizedGainsRelatedToChangesInFairValueOfOtherAssetsAndLiabilitiesRecordedInOtherIncome
Namespace Prefix: | rnr
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Net Unrealized Gains Related To Changes In Fair Value Of Secured Assets Recorded In Other Income + Details
Name: | rnr_NetUnrealizedGainsRelatedToChangesInFairValueOfSecuredAssetsRecordedInOtherIncome
Namespace Prefix: | rnr
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This item represents the weighted average effective yield percentage of debt securities. + Details
Name: | rnr_WeightedAverageEffectiveYieldPercentage
Namespace Prefix: | rnr
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Interest rate stated in the contractual debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 2, 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDateDescription
Namespace Prefix: | us-gaap
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 12 -Paragraph 3, 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 14 -Paragraph 2, 3 -Article 12 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 5 -Subparagraph (SX 210.12-13.Column C.6) -URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611282-123010 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 13 -Paragraph Column C -Article 12 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12.Column C.3,4) -URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611133-123010 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 13 -Paragraph 6 -Article 12 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14.Column E.2,3) -URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611322-123010 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 12 -Paragraph Column C -Article 12 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 14 -Paragraph Column E -Article 12 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 12C -Paragraph 7 -Article 12 Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-12C.Column C.7) -URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611225-123010 Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 12C -Paragraph Column C -Article 12 + Details
Name: | us-gaap_InvestmentOwnedAtFairValue
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. + Details
Name: | us-gaap_LongTermDebtFairValue
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16(a)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_SeniorNotes
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 + Details
Name: | us-gaap_UnrealizedGainLossOnInvestments
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration