v2.4.0.6

Investments Investments (Reverse Purchase Agreements) (Details) (USD $) In Millions, unless otherwise specified | Mar. 31, 2013 | Dec. 31, 2012
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Investments, Debt and Equity Securities [Abstract] |  |
Value of reverse repurchase agreements | $ 118.2 | $ 74.8
Minimum required collateral for reverse repurchase agreemetns, expressed as a percentage of loan principal | 102.00% |

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- Definition Securities Purchased Under Agreements To Resell Required Collateral Percentage Of Principal + References No definition available. + Details
Name: | rnr_SecuritiesPurchasedUnderAgreementsToResellRequiredCollateralPercentageOfPrincipal
Namespace Prefix: | rnr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition The carrying value of securities purchased to be resold in reverse repurchase transactions as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(m)(2)(i)) -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant