Condensed Consolidating Financial Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Statement Of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	$ 221,039	$ (1,638)
Cash flows (used in) provided by investing activities
Proceeds from sales and maturities of fixed maturity investments trading	2,682,386	2,540,073
Purchases of fixed maturity investments trading	(3,007,124)	(2,656,283)
Proceeds from sales and maturities of fixed maturity investments available for sale	0	3,662
Net sales of equity investments trading	13,747	119,369
Net sales of short term investments	245,693	134,009
Net sales (purchases) of other investments	36,402	(39,698)
Dividends and return of capital from subsidiaries	0	0
Contributions to subsidiaries	0	0
Due (from) to subsidiary	0	0
Net cash (used in) provided by investing activities	(28,896)	101,132
Cash flows used in financing activities
Dividends paid – RenaissanceRe common shares	(13,027)	(13,285)
Dividends paid – preference shares	(5,595)	(5,595)
RenaissanceRe common share repurchases	(80,009)	(85,166)
Net third party redeemable noncontrolling interest share transactions	(51,166)	(50,374)
Taxes paid on withholding shares	(11,018)	(8,069)
Net cash used in financing activities	(160,815)	(162,489)
Effect of exchange rate changes on foreign currency cash	1,602	5,259
Net increase (decrease) in cash and cash equivalents	32,930	(57,736)
Cash and cash equivalents, beginning of period	421,157	506,885	$ 506,885
Cash and cash equivalents, end of period	454,087	449,149	421,157
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	(12,358)	(12,542)
Cash flows (used in) provided by investing activities
Proceeds from sales and maturities of fixed maturity investments trading	38,449	80,763
Purchases of fixed maturity investments trading	(63,417)	(195,141)
Proceeds from sales and maturities of fixed maturity investments available for sale		0
Net sales of equity investments trading	0	0
Net sales of short term investments	269,585	104,213
Net sales (purchases) of other investments	0	0
Dividends and return of capital from subsidiaries	65,180	118,544
Contributions to subsidiaries	(162,550)	(19,924)
Due (from) to subsidiary	(28,130)	23,054
Net cash (used in) provided by investing activities	119,117	111,509
Cash flows used in financing activities
Dividends paid – RenaissanceRe common shares	(13,027)	(13,285)
Dividends paid – preference shares	(5,595)	(5,595)
RenaissanceRe common share repurchases	(80,009)	(85,166)
Net third party redeemable noncontrolling interest share transactions	0	0
Taxes paid on withholding shares	(11,018)	0
Net cash used in financing activities	(109,649)	(104,046)
Effect of exchange rate changes on foreign currency cash	0	0
Net increase (decrease) in cash and cash equivalents	(2,890)	(5,079)
Cash and cash equivalents, beginning of period	7,067	10,185	10,185
Cash and cash equivalents, end of period	4,177	5,106	7,067
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	(8,594)	(332)
Cash flows (used in) provided by investing activities
Proceeds from sales and maturities of fixed maturity investments trading	12,473	25,376
Purchases of fixed maturity investments trading	(12,438)	(82,697)
Proceeds from sales and maturities of fixed maturity investments available for sale		0
Net sales of equity investments trading	(74)	158
Net sales of short term investments	(590)	63,194
Net sales (purchases) of other investments	0	0
Dividends and return of capital from subsidiaries	9,175	2,900
Contributions to subsidiaries	0	0
Due (from) to subsidiary	50	(14,242)
Net cash (used in) provided by investing activities	8,596	(5,311)
Cash flows used in financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
RenaissanceRe common share repurchases	0	0
Net third party redeemable noncontrolling interest share transactions	0	0
Taxes paid on withholding shares	0	0
Net cash used in financing activities	0	0
Effect of exchange rate changes on foreign currency cash	0	0
Net increase (decrease) in cash and cash equivalents	2	(5,643)
Cash and cash equivalents, beginning of period	162	5,908	5,908
Cash and cash equivalents, end of period	164	265	162
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	5,188	4,561
Cash flows (used in) provided by investing activities
Proceeds from sales and maturities of fixed maturity investments trading	36,397	20,566
Purchases of fixed maturity investments trading	(36,790)	(135,561)
Proceeds from sales and maturities of fixed maturity investments available for sale		0
Net sales of equity investments trading	(2,181)	138,834
Net sales of short term investments	(5,087)	(33,409)
Net sales (purchases) of other investments	0	0
Dividends and return of capital from subsidiaries	0	0
Contributions to subsidiaries	0	0
Due (from) to subsidiary	(34)	139
Net cash (used in) provided by investing activities	(7,695)	(9,431)
Cash flows used in financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
RenaissanceRe common share repurchases	0	0
Net third party redeemable noncontrolling interest share transactions	0	0
Taxes paid on withholding shares	0	0
Net cash used in financing activities	0	0
Effect of exchange rate changes on foreign currency cash	0	0
Net increase (decrease) in cash and cash equivalents	(2,507)	(4,870)
Cash and cash equivalents, beginning of period	6,671	7,103	7,103
Cash and cash equivalents, end of period	4,164	2,233	6,671
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Cash flows (used in) provided by operating activities
Net cash provided by (used in) operating activities	(17,914)	(15,213)
Cash flows (used in) provided by investing activities
Proceeds from sales and maturities of fixed maturity investments trading	15,449	0
Purchases of fixed maturity investments trading	0	0
Proceeds from sales and maturities of fixed maturity investments available for sale		0
Net sales of equity investments trading	0	0
Net sales of short term investments	(3,374)	0
Net sales (purchases) of other investments	0	0
Dividends and return of capital from subsidiaries	9,175	0
Contributions to subsidiaries	(9,175)	0
Due (from) to subsidiary	2,522	20,979
Net cash (used in) provided by investing activities	14,597	20,979
Cash flows used in financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
RenaissanceRe common share repurchases	0	0
Net third party redeemable noncontrolling interest share transactions	0	0
Taxes paid on withholding shares	0	0
Net cash used in financing activities	0	0
Effect of exchange rate changes on foreign currency cash	0	0
Net increase (decrease) in cash and cash equivalents	(3,317)	5,766
Cash and cash equivalents, beginning of period	9,397	677	677
Cash and cash equivalents, end of period	6,080	6,443	9,397
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	254,717	21,888
Cash flows (used in) provided by investing activities
Proceeds from sales and maturities of fixed maturity investments trading	2,579,618	2,413,368
Purchases of fixed maturity investments trading	(2,894,479)	(2,242,884)
Proceeds from sales and maturities of fixed maturity investments available for sale		3,662
Net sales of equity investments trading	16,002	(19,623)
Net sales of short term investments	(14,841)	11
Net sales (purchases) of other investments	36,402	(39,698)
Dividends and return of capital from subsidiaries	(83,530)	(121,444)
Contributions to subsidiaries	171,725	19,924
Due (from) to subsidiary	25,592	(29,930)
Net cash (used in) provided by investing activities	(163,511)	(16,614)
Cash flows used in financing activities
Dividends paid – RenaissanceRe common shares	0	0
Dividends paid – preference shares	0	0
RenaissanceRe common share repurchases	0	0
Net third party redeemable noncontrolling interest share transactions	(51,166)	(50,374)
Taxes paid on withholding shares	0	(8,069)
Net cash used in financing activities	(51,166)	(58,443)
Effect of exchange rate changes on foreign currency cash	1,602	5,259
Net increase (decrease) in cash and cash equivalents	41,642	(47,910)
Cash and cash equivalents, beginning of period	397,860	483,012	483,012
Cash and cash equivalents, end of period	$ 439,502	$ 435,102	$ 397,860