Debt and Credit Facilities (Summary of Debt Obligations) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Fair Value	$ 1,201,347	$ 1,468,618
Carrying Value	$ 1,134,695	1,384,105
3.600% Senior Notes due 2029
Debt Instrument [Line Items]
Stated interest rate	3.60%
3.450% Senior Notes due 2027
Debt Instrument [Line Items]
Stated interest rate	3.45%
3.700% Senior Notes due 2025
Debt Instrument [Line Items]
Stated interest rate	3.70%
5.750% Senior Notes due 2020
Debt Instrument [Line Items]
Stated interest rate	5.75%
4.750% Senior Notes due 2025 (DaVinciRe)
Debt Instrument [Line Items]
Stated interest rate	4.75%
Senior Notes \| 3.600% Senior Notes due 2029 \| RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	$ 421,260	424,920
Carrying Value	391,703	391,475
Senior Notes \| 3.450% Senior Notes due 2027 \| RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	317,685	314,070
Carrying Value	296,415	296,292
Senior Notes \| 3.700% Senior Notes due 2025 \| RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	316,560	318,567
Carrying Value	298,150	298,057
Senior Notes \| 5.750% Senior Notes due 2020 \| RenaissanceRe Finance, Inc.
Debt Instrument [Line Items]
Fair Value	0	251,030
Carrying Value	0	249,931
Senior Notes \| 4.750% Senior Notes due 2025 (DaVinciRe) \| DaVinciRe Holdings Ltd.
Debt Instrument [Line Items]
Fair Value	145,842	160,031
Carrying Value	$ 148,427	$ 148,350

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-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=119400593&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-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 4: http://fasb.org/us-gaap/role/ref/legacyRef
-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

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=rnr_A3.600SeniorNotesDue2029Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rnr_A3.450SeniorNotesDueJuly12027Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rnr_A3.700SeniorNotesDueApril12025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rnr_A5.75SeniorNotesDueMarch152020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rnr_A4.750SeniorNotesDueMay12025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=rnr_RenaissanceReFinanceInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=rnr_DaVinciReHoldingsLtd.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: