This item represents the weighted average life in years of debt securities.

No definition available.

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- Definition

Estimated Liquidation Period of Assets, Minimum

+ References

No definition available.

+ Details

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- Definition

Estimated Liquidation Period of Limited Partnership Assets, Maximum

+ References

No definition available.

+ Details

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Namespace Prefix:	rnr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Estimated percentage return for the period on fair value at beginning of period.

+ References

No definition available.

+ Details

Name:	rnr_FairValueInputsEstimatedPerformance
Namespace Prefix:	rnr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This item represents senior secured bank loan funds in a closed end fund, which the Company has no right to redeem.

+ References

No definition available.

+ Details

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

- Definition

This item represents 'side pocket' investments which are not redeemable at the option of the shareholder.

+ References

No definition available.

+ Details

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

- Definition

Total Other Assets And liabilities Measured on Recurring Basis

+ References

No definition available.

+ Details

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

- Definition

This item represents the weighted average effective yield percentage of debt securities.

+ References

No definition available.

+ Details

Name:	rnr_WeightedAverageEffectiveYield
Namespace Prefix:	rnr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a recurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the 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

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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 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)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

+ Details

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- Definition

Adjustment to the discount rate used to measure fair value for lack of ability to convert business interests into cash quickly.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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- Definition

Risk associated with risk of default, credit spread risk and downgrade risk, expressed as a percentage, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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- Definition

Aggregation of the liabilities reported on the balance sheet measured at fair value on a recurring basis by the entity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- 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.

+ References

No definition available.

+ Details

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- 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 Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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Fair Value Measurements (Narrative) (Details) (USD $)	3 Months Ended			3 Months Ended												3 Months Ended				3 Months Ended		3 Months Ended					3 Months Ended														3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
Fair Value Measurements (Narrative) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 Other Investments Net investment income	Dec. 31, 2013 Other Investments Net investment income	Mar. 31, 2010 5.75% Senior Notes Due March 15, 2020 RenRe North America Holdings Inc.	Mar. 31, 2014 5.75% Senior Notes Due March 15, 2020 RenRe North America Holdings Inc.	Dec. 31, 2013 5.75% Senior Notes Due March 15, 2020 RenRe North America Holdings Inc.	Mar. 17, 2010 5.75% Senior Notes Due March 15, 2020 RenRe North America Holdings Inc.	Mar. 31, 2014 Significant Other Observable Inputs (Level 2)	Dec. 31, 2013 Significant Other Observable Inputs (Level 2)	Mar. 31, 2014 Significant Other Observable Inputs (Level 2) Cash Settled Restricted Stock Unit	Mar. 31, 2014 Fair Value, Inputs, (Level 3)	Dec. 31, 2013 Fair Value, Inputs, (Level 3)	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Hedge funds Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Hedge funds Minimum Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Hedge funds Maximum Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Hedge funds Weighted Average or Actual Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Senior secured bank loan funds Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Senior secured bank loan funds Weighted Average or Actual Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Private equity partnerships Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Private equity partnerships Minimum Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Private equity partnerships Maximum Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Private equity partnerships Weighted Average or Actual Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Corporate Discounted Cash Flow Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Corporate Internal Valuation Model Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Corporate Weighted Average or Actual Discounted Cash Flow Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 3) Private Equity Funds Net Asset Valuation Technique	Mar. 31, 2014 Fair Value, Inputs, (Level 1)	Dec. 31, 2013 Fair Value, Inputs, (Level 1)	Mar. 31, 2014 U.S. treasuries	Dec. 31, 2013 U.S. treasuries	Mar. 31, 2014 Agencies	Dec. 31, 2013 Agencies	Mar. 31, 2014 Non-U.S. government (Sovereign Debt)	Dec. 31, 2013 Non-U.S. government (Sovereign Debt)	Mar. 31, 2014 Non-U.S. government-backed corporate	Dec. 31, 2013 Non-U.S. government-backed corporate	Mar. 31, 2014 Corporate	Dec. 31, 2013 Corporate	Mar. 31, 2014 Agency mortgage-backed	Dec. 31, 2013 Agency mortgage-backed	Mar. 31, 2014 Non-agency prime residential mortgage-backed	Dec. 31, 2013 Non-agency prime residential mortgage-backed	Mar. 31, 2014 AltA non-agency mortgage-backed	Dec. 31, 2013 AltA non-agency mortgage-backed	Mar. 31, 2014 Commercial mortgage-backed	Dec. 31, 2013 Commercial mortgage-backed	Mar. 31, 2014 Asset-backed	Dec. 31, 2013 Asset-backed	Mar. 31, 2014 Senior secured bank loan funds	Mar. 31, 2014 Private equity partnerships	Mar. 31, 2014 Hedge funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities, fair value													$ 1,307,000
Weighted average effective yield																															0.90%	0.80%	1.60%	1.30%	1.10%	1.30%	1.30%	1.10%	2.90%	2.70%	2.70%	2.90%	3.30%	3.70%	4.30%	4.70%	2.10%	2.10%	1.60%	2.00%
Weighted average life																																									6 years 0 months 0 days	6 years 2 months 12 days	4 years 4 months 24 days	4 years 4 months 24 days	4 years 4 months 24 days	4 years	3 years 9 months 18 days	3 years 3 months 18 days	2 years 9 months 18 days	3 years 6 months
Assets and (liabilities) at fair value	3,428,000		(8,233,000)							4,059,000	(6,566,000)	(1,400,000)	(1,307,000)	(2,490,000)															676,000	823,000
Assets, fair value													378,609,000		3,411,000				13,656,000		325,711,000				15,846,000	21,292,000		325,711,000
Dividend rate																											6.20%
Liquidity discount																											1.00%
Risk-free rate																											0.30%
Credit spread																											2.10%
Estimated performance																0.00%	0.00%	0.00%		0.90%		(4.40%)	75.50%	4.10%
5.75% Senior notes issued									250,000,000
Senior notes interest rate							5.75%
Debt instrument maturity date						March 15, 2020
Senior Notes, Fair value							264,200,000	273,900,000
Net unrealized gains (losses) recognized in earnings	4,980,000	15,071,000		5,000,000	15,100,000
Minimum estimated liquidation period																																																			4 years	7 years
Maximum estimated liquidation period																																																			5 years	10 years
Investment in closed end fund																																																			13,700,000
Hedge fund side pocket investments																																																					$ 3,400,000