v2.3.0.15

Derivative Instruments (Gross Derivative Contract Positions Outstanding Relating To Energy And Weather Derivatives Trading Activities) (Details)	Sep. 30, 2011 Btu bushels		Dec. 31, 2010 bushels Btu
Derivative Instruments
Energy	170,550,283	[1]	136,767,119	[1]
Temperature	12,896,109	[1]	5,419,846	[1]
Agriculture	12,008,000	[1]	260,000	[1]
[1] Represents the sum of gross long and gross short derivative contracts.

X

- Definition

The quantity of agriculture derivative contracts represented as the sum of gross long and gross short contract positions.

+ Details

Name:	rnr_SumOfGrossLongAndShortAgricultureDerivativeContracts
Namespace Prefix:	rnr
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The quantity of energy derivative contracts represented as the sum of gross long and gross short contract positions.

+ Details

Name:	rnr_SumOfGrossLongAndShortEnergyDerivativeContracts
Namespace Prefix:	rnr
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The quantity of temperature derivative contracts represented as the sum of gross long and gross short contract positions.

+ Details

Name:	rnr_SumOfGrossLongAndShortTemperatureDerivativeContracts
Namespace Prefix:	rnr
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_SummaryOfDerivativeInstrumentsAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration