Statutory Requirements (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Statutory Accounting Practices [Line Items]
Assets held in trust	$ 8,100,000	$ 7,000,000
U.S.
Statutory Accounting Practices [Line Items]
Unrestricted net assets	71,517	46,630
New York \| Multi-Beneficiary Reinsurance Trust \| Renaissance Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Assets held in trust	1,300,000	1,300,000
New York \| Multi-Beneficiary Reinsurance Trust \| Renaissance Reinsurance Ltd. \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	878,200	927,400
New York \| Multi-Beneficiary Reinsurance Trust \| DaVinci Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Assets held in trust	289,600	336,500
New York \| Multi-Beneficiary Reinsurance Trust \| DaVinci Reinsurance Ltd. \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	270,500	249,400
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| Renaissance Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Assets held in trust	74,400	51,700
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| Renaissance Reinsurance Ltd. \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	70,000	40,300
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| DaVinci Reinsurance Ltd.
Statutory Accounting Practices [Line Items]
Assets held in trust	90,100	43,800
New York \| Multi-Beneficiary Reduced Collateral Reinsurance Trust \| DaVinci Reinsurance Ltd. \| Low
Statutory Accounting Practices [Line Items]
Assets held in trust	$ 86,500	$ 40,900
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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- 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://fasb.org/us-gaap/role/ref/legacyRef
-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.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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- Details

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