Condensed Consolidating Financial Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Statement of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	$ (703,494)	$ 188,061	$ (356,870)	$ 538,798
Change in net unrealized gains on investments	300	284	(972)	513
Comprehensive (loss) income	(703,194)	188,345	(357,842)	539,311
Net loss (income) attributable to redeemable noncontrolling interests	204,277	(35,641)	132,338	(110,867)
Comprehensive loss attributable to redeemable noncontrolling interests	204,277	(35,641)	132,338	(110,867)
Comprehensive (loss) income attributable to RenaissanceRe	(498,917)	152,704	(225,504)	428,444
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	2,751	2,941	8,569	6,109
Change in net unrealized gains on investments	0	0	0	0
Comprehensive (loss) income	2,751	2,941	8,569	6,109
Net loss (income) attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive loss attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive (loss) income attributable to RenaissanceRe	2,751	2,941	8,569	6,109
Reportable Legal Entities | Platinum Underwriters Finance, Inc. (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	25	(1,731)	30,595	36,096
Change in net unrealized gains on investments	0	0	0	0
Comprehensive (loss) income	25	(1,731)	30,595	36,096
Net loss (income) attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive loss attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive (loss) income attributable to RenaissanceRe	25	(1,731)	30,595	36,096
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	(27,145)	(7,511)	(12,214)	15,409
Change in net unrealized gains on investments	0	0	0	0
Comprehensive (loss) income	(27,145)	(7,511)	(12,214)	15,409
Net loss (income) attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive loss attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive (loss) income attributable to RenaissanceRe	(27,145)	(7,511)	(12,214)	15,409
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	(499,217)	152,420	(224,532)	427,931
Change in net unrealized gains on investments	0	0	0	0
Comprehensive (loss) income	(499,217)	152,420	(224,532)	427,931
Net loss (income) attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive loss attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive (loss) income attributable to RenaissanceRe	(499,217)	152,420	(224,532)	427,931
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries And Eliminations (Non-Guarantor Subsidiaries)
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	(692,646)	203,405	(323,085)	561,078
Change in net unrealized gains on investments	300	284	(972)	513
Comprehensive (loss) income	(692,346)	203,689	(324,057)	561,591
Net loss (income) attributable to redeemable noncontrolling interests	204,277	(35,641)	132,338	(110,867)
Comprehensive loss attributable to redeemable noncontrolling interests	204,277	(35,641)	132,338	(110,867)
Comprehensive (loss) income attributable to RenaissanceRe	(488,069)	168,048	(191,719)	450,724
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	512,738	(161,463)	163,797	(507,825)
Change in net unrealized gains on investments	0	0	0	0
Comprehensive (loss) income	512,738	(161,463)	163,797	(507,825)
Net loss (income) attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive loss attributable to redeemable noncontrolling interests	0	0	0	0
Comprehensive (loss) income attributable to RenaissanceRe	$ 512,738	$ (161,463)	$ 163,797	$ (507,825)