Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries (Condensed Consolidating Statement of Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ (123,986)	$ 48,829	$ 251,867	$ 92,207	$ 2,199	$ (703,494)	$ 214,350	$ 132,274	$ 268,917	$ (354,671)	$ 630,048
Change in net unrealized (losses) gains on investments									(1,657)	(909)	(975)
Comprehensive income (loss)									267,260	(355,580)	629,073
Net (income) loss attributable to redeemable noncontrolling interests									(41,553)	132,282	(127,086)
Comprehensive income attributable to redeemable noncontrolling interests									(41,553)	132,282	(127,086)
Comprehensive income (loss) attributable to RenaissanceRe									225,707	(223,298)	501,987
RenaissanceRe Holdings Ltd. (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Comprehensive income (loss) attributable to RenaissanceRe									227,364	(222,389)	502,962
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									227,364	(222,389)	502,962
Change in net unrealized (losses) gains on investments									0	0	0
Comprehensive income (loss)									227,364	(222,389)	502,962
Net (income) loss attributable to redeemable noncontrolling interests									0	0	0
Comprehensive income attributable to redeemable noncontrolling interests									0	0	0
Comprehensive income (loss) attributable to RenaissanceRe									227,364	(222,389)	502,962
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries And Eliminations (Non-Guarantor Subsidiaries)
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									349,780	(285,838)	681,025
Change in net unrealized (losses) gains on investments									(1,657)	(909)	(975)
Comprehensive income (loss)									348,123	(286,747)	680,050
Net (income) loss attributable to redeemable noncontrolling interests									(41,553)	132,282	(127,086)
Comprehensive income attributable to redeemable noncontrolling interests									(41,553)	132,282	(127,086)
Comprehensive income (loss) attributable to RenaissanceRe									306,570	(154,465)	552,964
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									3,936	(5,926)	8,002
Change in net unrealized (losses) gains on investments									0	0	0
Comprehensive income (loss)									3,936	(5,926)	8,002
Net (income) loss attributable to redeemable noncontrolling interests									0	0	0
Comprehensive income attributable to redeemable noncontrolling interests									0	0	0
Comprehensive income (loss) attributable to RenaissanceRe									3,936	(5,926)	8,002
Reportable Legal Entities | Platinum Underwriters Finance, Inc. (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Net income (loss)										30,596	29,591
Change in net unrealized (losses) gains on investments										0	0
Comprehensive income (loss)										30,596	29,591
Net (income) loss attributable to redeemable noncontrolling interests										0	0
Comprehensive income attributable to redeemable noncontrolling interests										0	0
Comprehensive income (loss) attributable to RenaissanceRe										30,596	29,591
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									(47,395)	(38,871)	1,922
Change in net unrealized (losses) gains on investments									0	0	0
Comprehensive income (loss)									(47,395)	(38,871)	1,922
Net (income) loss attributable to redeemable noncontrolling interests									0	0	0
Comprehensive income attributable to redeemable noncontrolling interests									0	0	0
Comprehensive income (loss) attributable to RenaissanceRe									(47,395)	(38,871)	1,922
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									(264,768)	167,757	(593,454)
Change in net unrealized (losses) gains on investments									0	0	0
Comprehensive income (loss)									(264,768)	167,757	(593,454)
Net (income) loss attributable to redeemable noncontrolling interests									0	0	0
Comprehensive income attributable to redeemable noncontrolling interests									0	0	0
Comprehensive income (loss) attributable to RenaissanceRe									$ (264,768)	$ 167,757	$ (593,454)