Condensed Consolidating Financial Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Statement Of Cash Flows) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	$ 370,003	$ 162,147
Cash flows provided by (used in) investing activities
Proceeds from sales and maturities of fixed maturity investments trading	6,509,019	6,956,729
Purchases of fixed maturity investments trading	(6,744,838)	(7,194,793)
Proceeds from sales and maturities of fixed maturity investments available for sale	5,931	6,741
Net sales (purchases) of equity investments trading	183,112	(153,452)
Net sales of short term investments	128,869	896,027
Net (purchases) sales of other investments	(56,765)	7,033
Net purchases of investments in other ventures	0	(45)
Net sales of other assets	400	4,500
Dividends and return of capital from subsidiaries	0	0
Contributions to subsidiaries	0	0
Due (from) to subsidiary	0	0
Net purchase of Platinum	0	(678,152)
Net cash provided by (used in) investing activities	25,728	(155,412)
Cash flows (used in) provided by financing activities
Dividends paid – RenaissanceRe common shares	(38,886)	(40,883)
Dividends paid – preference shares	(16,786)	(16,786)
RenaissanceRe common share repurchases	(309,434)	(197,350)
Net issuance of debt	0	445,589
Net third party redeemable noncontrolling interest share transactions	(45,496)	(187,339)
Net cash (used in) provided by financing activities	(410,602)	3,231
Effect of exchange rate changes on foreign currency cash	1,316	(11,004)
Net decrease in cash and cash equivalents	(13,555)	(1,038)
Cash and cash equivalents, beginning of period	506,885	525,584	$ 525,584
Cash and cash equivalents, end of period	493,330	524,546	506,885
RenaissanceRe Holdings Ltd. (Parent Guarantor)
Cash flows provided by (used in) investing activities
Net sales of other assets	0
RenRe North America Holdings Inc. (Subsidiary Issuer)
Cash flows provided by (used in) investing activities
Net sales of other assets	0
Platinum Underwriters Finance, Inc. (Subsidiary Issuer)
Cash flows provided by (used in) investing activities
Net sales of other assets	0
RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Cash flows provided by (used in) investing activities
Net sales of other assets	0
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	(7,644)	(34,806)
Cash flows provided by (used in) investing activities
Proceeds from sales and maturities of fixed maturity investments trading	272,710	39,429
Purchases of fixed maturity investments trading	(336,345)	(119,725)
Proceeds from sales and maturities of fixed maturity investments available for sale	0	0
Net sales (purchases) of equity investments trading	0	0
Net sales of short term investments	122,656	26,847
Net (purchases) sales of other investments	0	0
Net purchases of investments in other ventures		0
Net sales of other assets		0
Dividends and return of capital from subsidiaries	408,189	1,260,632
Contributions to subsidiaries	(91,001)	(287,889)
Due (from) to subsidiary	(3,497)	281,726
Net purchase of Platinum		(904,433)
Net cash provided by (used in) investing activities	372,712	296,587
Cash flows (used in) provided by financing activities
Dividends paid – RenaissanceRe common shares	(38,886)	(40,883)
Dividends paid – preference shares	(16,786)	(16,786)
RenaissanceRe common share repurchases	(309,434)	(197,350)
Net issuance of debt		0
Net third party redeemable noncontrolling interest share transactions	0	0
Net cash (used in) provided by financing activities	(365,106)	(255,019)
Effect of exchange rate changes on foreign currency cash	0	0
Net decrease in cash and cash equivalents	(38)	6,762
Cash and cash equivalents, beginning of period	10,185	5,986	5,986
Cash and cash equivalents, end of period	10,147	12,748	10,185
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	1,847	(2,814)
Cash flows provided by (used in) investing activities
Proceeds from sales and maturities of fixed maturity investments trading	62,959	29,074
Purchases of fixed maturity investments trading	(115,849)	(42,840)
Proceeds from sales and maturities of fixed maturity investments available for sale	0	0
Net sales (purchases) of equity investments trading	(2,392)	33,682
Net sales of short term investments	67,986	1,133
Net (purchases) sales of other investments	0	0
Net purchases of investments in other ventures		0
Net sales of other assets		0
Dividends and return of capital from subsidiaries	2,900	180,000
Contributions to subsidiaries	0	(13,850)
Due (from) to subsidiary	(22,502)	(183,621)
Net purchase of Platinum		0
Net cash provided by (used in) investing activities	(6,898)	3,578
Cash flows (used in) provided by financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
RenaissanceRe common share repurchases	0	0
Net issuance of debt		0
Net third party redeemable noncontrolling interest share transactions	0	0
Net cash (used in) provided by financing activities	0	0
Effect of exchange rate changes on foreign currency cash	0	0
Net decrease in cash and cash equivalents	(5,051)	764
Cash and cash equivalents, beginning of period	5,908	1,033	1,033
Cash and cash equivalents, end of period	857	1,797	5,908
Reportable Legal Entities | Platinum Underwriters Finance, Inc. (Subsidiary Issuer)
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	(11,062)	(7,564)
Cash flows provided by (used in) investing activities
Proceeds from sales and maturities of fixed maturity investments trading	113,947	45,087
Purchases of fixed maturity investments trading	(259,165)	0
Proceeds from sales and maturities of fixed maturity investments available for sale	0	0
Net sales (purchases) of equity investments trading	192,911	(274,567)
Net sales of short term investments	(41,881)	236,548
Net (purchases) sales of other investments	0	0
Net purchases of investments in other ventures		0
Net sales of other assets		0
Dividends and return of capital from subsidiaries	0	0
Contributions to subsidiaries	0	0
Due (from) to subsidiary	(108)	20
Net purchase of Platinum		1,537
Net cash provided by (used in) investing activities	5,704	8,625
Cash flows (used in) provided by financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
RenaissanceRe common share repurchases	0	0
Net issuance of debt		0
Net third party redeemable noncontrolling interest share transactions	0	0
Net cash (used in) provided by financing activities	0	0
Effect of exchange rate changes on foreign currency cash	0	0
Net decrease in cash and cash equivalents	(5,358)	1,061
Cash and cash equivalents, beginning of period	7,103	0	0
Cash and cash equivalents, end of period	1,745	1,061	7,103
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	(35,171)	(11,756)
Cash flows provided by (used in) investing activities
Proceeds from sales and maturities of fixed maturity investments trading	0	0
Purchases of fixed maturity investments trading	0	0
Proceeds from sales and maturities of fixed maturity investments available for sale	0	0
Net sales (purchases) of equity investments trading	0	0
Net sales of short term investments	0	0
Net (purchases) sales of other investments	0	0
Net purchases of investments in other ventures		0
Net sales of other assets		0
Dividends and return of capital from subsidiaries	9,300	20,800
Contributions to subsidiaries	0	(185,000)
Due (from) to subsidiary	27,724	(116,709)
Net purchase of Platinum		0
Net cash provided by (used in) investing activities	37,024	(280,909)
Cash flows (used in) provided by financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
RenaissanceRe common share repurchases	0	0
Net issuance of debt		299,400
Net third party redeemable noncontrolling interest share transactions	0	0
Net cash (used in) provided by financing activities	0	299,400
Effect of exchange rate changes on foreign currency cash	0	0
Net decrease in cash and cash equivalents	1,853	6,735
Cash and cash equivalents, beginning of period	677	0	0
Cash and cash equivalents, end of period	2,530	6,735	677
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries And Eliminations (Non-Guarantor Subsidiaries)
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	422,033	219,087
Cash flows provided by (used in) investing activities
Proceeds from sales and maturities of fixed maturity investments trading	6,059,403	6,843,139
Purchases of fixed maturity investments trading	(6,033,479)	(7,032,228)
Proceeds from sales and maturities of fixed maturity investments available for sale	5,931	6,741
Net sales (purchases) of equity investments trading	(7,407)	87,433
Net sales of short term investments	(19,892)	631,499
Net (purchases) sales of other investments	(56,765)	7,033
Net purchases of investments in other ventures		(45)
Net sales of other assets	400	4,500
Dividends and return of capital from subsidiaries	(420,389)	(1,461,432)
Contributions to subsidiaries	91,001	486,739
Due (from) to subsidiary	(1,617)	18,584
Net purchase of Platinum		224,744
Net cash provided by (used in) investing activities	(382,814)	(183,293)
Cash flows (used in) provided by financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
RenaissanceRe common share repurchases	0	0
Net issuance of debt		146,189
Net third party redeemable noncontrolling interest share transactions	(45,496)	(187,339)
Net cash (used in) provided by financing activities	(45,496)	(41,150)
Effect of exchange rate changes on foreign currency cash	1,316	(11,004)
Net decrease in cash and cash equivalents	(4,961)	(16,360)
Cash and cash equivalents, beginning of period	483,012	518,565	518,565
Cash and cash equivalents, end of period	$ 478,051	$ 502,205	$ 483,012