Statutory Requirements (Narrative) (Details) - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Statutory Accounting Practices [Line Items]
Assets held in trust	$ 8,700,000,000	$ 8,100,000,000
U.S.
Statutory Accounting Practices [Line Items]
Unrestricted net assets	81,981,000	72,272,000
New York \| Multi-Beneficiary Reinsurance Trust \| Renaissance Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Assets held in trust	1,200,000,000	1,300,000,000
New York \| Multi-Beneficiary Reinsurance Trust \| Renaissance Reinsurance Ltd. \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	531,800,000	878,200,000
New York \| Multi-Beneficiary Reinsurance Trust \| DaVinci Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Assets held in trust	272,000,000	289,600,000
New York \| Multi-Beneficiary Reinsurance Trust \| DaVinci Reinsurance Ltd. \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	182,300,000	270,500,000
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| Renaissance Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Assets held in trust	136,300,000	74,400,000
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| Renaissance Reinsurance Ltd. \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	128,100,000	70,000,000
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| RenaissanceRe Europe
Statutory Accounting Practices [Line Items]
Assets held in trust	86,600,000	0
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| RenaissanceRe Europe \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	75,800,000	0
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| DaVinci Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Assets held in trust	168,100,000	90,100,000
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| DaVinci Reinsurance Ltd. \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	$ 164,500,000	$ 86,500,000
Florida \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| Renaissance Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Multi-beneficiary reduced collateral reinsurance trust collateral reduction	20.00%
Florida \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| RenaissanceRe Europe
Statutory Accounting Practices [Line Items]
Multi-beneficiary reduced collateral reinsurance trust collateral reduction	20.00%
Florida \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| DaVinci Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Multi-beneficiary reduced collateral reinsurance trust collateral reduction	50.00%

Reduction in collateral requirements of multi-beneficiary reinsurance trust to the percentage noted of the net outstanding insurance liabilities.

No definition available.

+ Details

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Namespace Prefix:	rnr_
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Balance Type:	na
Period Type:	duration

- Definition

The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(b))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of dividends that can be declared or paid without approval of regulatory agency.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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