v2.4.0.6

Segment Reporting (Narrative) (Details) | 6 Months Ended
--- | ---
Jun. 30, 2012 segments
Segment Reporting Information [Line Items] |
Reportable Segments | 3
Insurance [Member] |
Segment Reporting Information [Line Items] |
Number of States in which Glencoe Operates | 49

X
- Definition Disclosure of the number of segments reported by the entity. + References No definition available. + Details
Name: | rnr_NumberOfReportableSegments
Namespace Prefix: | rnr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of states the entity operates in as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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