Debt and Credit Facilities (Summary of Debt Obligations) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Fair Value	$ 987,400	$ 1,000,000
Carrying Value	$ 990,371	989,623
3.450% Senior Notes due 2027
Debt Instrument [Line Items]
Debt instrument, Interest rate	3.45%
3.700% Senior Notes due 2025
Debt Instrument [Line Items]
Debt instrument, Interest rate	3.70%
5.750% Senior Notes due 2020
Debt Instrument [Line Items]
Debt instrument, Interest rate	5.75%
4.750% Senior Notes due 2025 (DaVinciRe)
Debt Instrument [Line Items]
Debt instrument, Interest rate	4.75%
Senior Notes
Debt Instrument [Line Items]
Fair Value	$ 987,435	1,018,235
Carrying Value	990,371	989,623
Senior Notes \| 3.450% Senior Notes due 2027 \| RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	283,725	294,654
Carrying Value	295,549	295,303
Senior Notes \| 3.700% Senior Notes due 2025
Debt Instrument [Line Items]
Fair Value	294,573	302,781
Carrying Value	297,501	297,318
Senior Notes \| 5.750% Senior Notes due 2020
Debt Instrument [Line Items]
Fair Value	258,750	263,750
Carrying Value	249,436	249,272
Senior Notes \| 4.750% Senior Notes due 2025 (DaVinciRe) \| DaVinciRe Holdings Ltd.
Debt Instrument [Line Items]
Fair Value	150,387	157,050
Carrying Value	$ 147,885	$ 147,730

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: 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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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: 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))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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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.

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