Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries (Condensed Consolidating Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Net premiums earned	$ 970,125	$ 906,748	$ 911,502	$ 550,028	$ 574,613	$ 531,849	$ 429,385	$ 440,282	$ 3,338,403	$ 1,976,129	$ 1,717,575
Net investment income	112,695	113,844	115,832	81,462	53,338	80,696	71,356	56,476	423,833	261,866	222,209
Net foreign exchange (losses) gains	(1,126)	(8,275)	9,309	(2,846)	(932)	(4,566)	(10,687)	3,757	(2,938)	(12,428)	10,628
Equity in earnings of other ventures	5,874	5,877	6,812	4,661	4,143	7,648	5,826	857	23,224	18,474	8,030
Other loss	(160)	1,016	922	3,171	5,489	497	1,225	(1,242)	4,949	5,969	9,415
Net realized and unrealized gains (losses) on investments	17,897	31,938	194,003	170,645	(88,654)	13,630	(17,901)	(82,144)	414,483	(175,069)	135,822
Total revenues	1,105,305	1,051,148	1,238,380	807,121	547,997	629,754	479,204	417,986	4,201,954	2,074,941	2,103,679
Expenses
Net claims and claim expenses incurred	762,093	654,520	453,373	227,035	477,638	410,510	60,167	171,703	2,097,021	1,120,018	1,861,428
Acquisition expenses	208,618	202,181	227,482	123,951	120,465	109,761	105,052	97,711	762,232	432,989	346,892
Operational expenses	64,571	53,415	59,814	44,933	58,859	40,593	37,543	41,272	222,733	178,267	160,778
Corporate expenses	17,642	13,844	23,847	38,789	12,108	6,841	8,301	6,733	94,122	33,983	18,572
Interest expense	15,496	15,580	15,534	11,754	11,765	11,769	11,768	11,767	58,364	47,069	44,193
Total expenses	1,068,420	939,540	780,050	446,462	680,835	579,474	222,831	329,186	3,234,472	1,812,326	2,431,863
(Loss) income before equity in net (loss) income of subsidiaries and taxes									967,482	262,615	(328,184)
Equity in net income of subsidiaries									0	0	0
Income (loss) before taxes	36,885	111,608	458,330	360,659	(132,838)	50,280	256,373	88,800	967,482	262,615	(328,184)
Income tax (expense) benefit	3,455	(3,664)	(9,475)	(7,531)	8,852	(1,451)	(4,506)	3,407	(17,215)	6,302	(26,487)
Net income (loss)	40,340	107,944	448,855	353,128	(123,986)	48,829	251,867	92,207	950,267	268,917	(354,671)
Net (income) loss attributable to redeemable noncontrolling interests	2,622	(62,057)	(71,812)	(70,222)	49,269	(6,440)	(54,483)	(29,899)	(201,469)	(41,553)	132,282
Net income (loss) attributable to RenaissanceRe	42,962	45,887	377,043	282,906	(74,717)	42,389	197,384	62,308	748,798	227,364	(222,389)
Dividends on preference shares	(9,189)	(9,189)	(9,189)	(9,189)	(9,189)	(9,708)	(5,596)	(5,595)	(36,756)	(30,088)	(22,381)
Net income (loss) available (attributable) to RenaissanceRe common shareholders	$ 33,773	$ 36,698	$ 367,854	$ 273,717	$ (83,906)	$ 32,681	$ 191,788	$ 56,713	712,042	197,276	(244,770)
RenaissanceRe Holdings Ltd. (Parent Guarantor)
Revenues
Net investment income									39,629	24,791	23,109
Net foreign exchange (losses) gains									7,342	(3)	(1)
Net realized and unrealized gains (losses) on investments									12,393	633	(1,357)
Total revenues									59,364	25,421	21,751
Expenses
Operational expenses									7,506	7,679	11,314
Corporate expenses									58,393	25,190	18,546
Interest expense									18,086	5,683	1,572
Total expenses									83,985	38,552	31,432
(Loss) income before equity in net (loss) income of subsidiaries and taxes									(24,621)	(13,131)	(9,681)
Equity in net income of subsidiaries									773,419	240,495	(212,708)
Net income (loss) attributable to RenaissanceRe									748,798	227,364	(222,389)
Dividends on preference shares									(36,756)	(30,088)	(22,381)
Net income (loss) available (attributable) to RenaissanceRe common shareholders									712,042	197,276	(244,770)
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Revenues
Net premiums earned									0	0	0
Net investment income									39,629	24,791	23,109
Net foreign exchange (losses) gains									7,342	(3)	(1)
Equity in earnings of other ventures									0	0	0
Other loss									0	0	0
Net realized and unrealized gains (losses) on investments									12,393	633	(1,357)
Total revenues									59,364	25,421	21,751
Expenses
Net claims and claim expenses incurred									0	0	0
Acquisition expenses									0	0	0
Operational expenses									7,506	7,679	11,314
Corporate expenses									58,393	25,190	18,546
Interest expense									18,086	5,683	1,572
Total expenses									83,985	38,552	31,432
(Loss) income before equity in net (loss) income of subsidiaries and taxes									(24,621)	(13,131)	(9,681)
Equity in net income of subsidiaries									773,419	240,495	(212,708)
Income (loss) before taxes									748,798	227,364	(222,389)
Income tax (expense) benefit									0	0	0
Net income (loss)									748,798	227,364	(222,389)
Net (income) loss attributable to redeemable noncontrolling interests									0	0	0
Net income (loss) attributable to RenaissanceRe									748,798	227,364	(222,389)
Dividends on preference shares									(36,756)	(30,088)	(22,381)
Net income (loss) available (attributable) to RenaissanceRe common shareholders									712,042	197,276	(244,770)
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries And Eliminations (Non-Guarantor Subsidiaries)
Revenues
Net premiums earned									3,338,403	1,976,129	1,717,575
Net investment income									419,502	261,192	219,490
Net foreign exchange (losses) gains									(10,280)	(12,425)	10,629
Equity in earnings of other ventures									19,338	15,409	8,253
Other loss									4,949	5,969	9,415
Net realized and unrealized gains (losses) on investments									380,382	(171,013)	123,121
Total revenues									4,152,294	2,075,261	2,088,483
Expenses
Net claims and claim expenses incurred									2,097,021	1,120,018	1,861,428
Acquisition expenses									762,232	432,989	346,892
Operational expenses									207,981	164,605	141,572
Corporate expenses									43,413	3,103	26
Interest expense									2,285	4,367	10,075
Total expenses									3,112,932	1,725,082	2,359,993
(Loss) income before equity in net (loss) income of subsidiaries and taxes									1,039,362	350,179	(271,510)
Equity in net income of subsidiaries									0	0	0
Income (loss) before taxes									1,039,362	350,179	(271,510)
Income tax (expense) benefit									(18,853)	(399)	(14,328)
Net income (loss)									1,020,509	349,780	(285,838)
Net (income) loss attributable to redeemable noncontrolling interests									(201,469)	(41,553)	132,282
Net income (loss) attributable to RenaissanceRe									819,040	308,227	(153,556)
Dividends on preference shares									0	0	0
Net income (loss) available (attributable) to RenaissanceRe common shareholders									819,040	308,227	(153,556)
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Revenues
Net premiums earned									0	0	0
Net investment income									2,318	2,193	1,947
Net foreign exchange (losses) gains									0	0	0
Equity in earnings of other ventures									0	0	0
Other loss									0	0	0
Net realized and unrealized gains (losses) on investments									21,557	(4,360)	9,621
Total revenues									23,875	(2,167)	11,568
Expenses
Net claims and claim expenses incurred									0	0	0
Acquisition expenses									0	0	0
Operational expenses									56	110	103
Corporate expenses									0	0	0
Interest expense									0	0	0
Total expenses									56	110	103
(Loss) income before equity in net (loss) income of subsidiaries and taxes									23,819	(2,277)	11,465
Equity in net income of subsidiaries									5,611	5,631	756
Income (loss) before taxes									29,430	3,354	12,221
Income tax (expense) benefit									(4,872)	582	(18,147)
Net income (loss)									24,558	3,936	(5,926)
Net (income) loss attributable to redeemable noncontrolling interests									0	0	0
Net income (loss) attributable to RenaissanceRe									24,558	3,936	(5,926)
Dividends on preference shares									0	0	0
Net income (loss) available (attributable) to RenaissanceRe common shareholders									24,558	3,936	(5,926)
Reportable Legal Entities | Platinum Underwriters Finance, Inc. (Subsidiary Issuer)
Revenues
Net premiums earned											0
Net investment income											1,373
Net foreign exchange (losses) gains											0
Equity in earnings of other ventures											0
Other loss											0
Net realized and unrealized gains (losses) on investments											4,916
Total revenues											6,289
Expenses
Net claims and claim expenses incurred											0
Acquisition expenses											0
Operational expenses											85
Corporate expenses											0
Interest expense											2,461
Total expenses											2,546
(Loss) income before equity in net (loss) income of subsidiaries and taxes											3,743
Equity in net income of subsidiaries											28,028
Income (loss) before taxes											31,771
Income tax (expense) benefit											(1,175)
Net income (loss)											30,596
Net (income) loss attributable to redeemable noncontrolling interests											0
Net income (loss) attributable to RenaissanceRe											30,596
Dividends on preference shares											0
Net income (loss) available (attributable) to RenaissanceRe common shareholders											30,596
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Revenues
Net premiums earned									0	0	0
Net investment income									7,547	6,219	3,090
Net foreign exchange (losses) gains									0	0	0
Equity in earnings of other ventures									3,886	3,065	(223)
Other loss									0	0	0
Net realized and unrealized gains (losses) on investments									151	(329)	(479)
Total revenues									11,584	8,955	2,388
Expenses
Net claims and claim expenses incurred									0	0	0
Acquisition expenses									0	0	0
Operational expenses									38,487	34,534	26,063
Corporate expenses									16	7	0
Interest expense									37,993	37,019	31,657
Total expenses									76,496	71,560	57,720
(Loss) income before equity in net (loss) income of subsidiaries and taxes									(64,912)	(62,605)	(55,332)
Equity in net income of subsidiaries									99,148	9,091	9,298
Income (loss) before taxes									34,236	(53,514)	(46,034)
Income tax (expense) benefit									6,510	6,119	7,163
Net income (loss)									40,746	(47,395)	(38,871)
Net (income) loss attributable to redeemable noncontrolling interests									0	0	0
Net income (loss) attributable to RenaissanceRe									40,746	(47,395)	(38,871)
Dividends on preference shares									0	0	0
Net income (loss) available (attributable) to RenaissanceRe common shareholders									40,746	(47,395)	(38,871)
Consolidating Adjustments
Revenues
Net premiums earned									0	0	0
Net investment income									(45,163)	(32,529)	(26,800)
Net foreign exchange (losses) gains									0	0	0
Equity in earnings of other ventures									0	0	0
Other loss									0	0	0
Net realized and unrealized gains (losses) on investments									0	0	0
Total revenues									(45,163)	(32,529)	(26,800)
Expenses
Net claims and claim expenses incurred									0	0	0
Acquisition expenses									0	0	0
Operational expenses									(31,297)	(28,661)	(18,359)
Corporate expenses									(7,700)	5,683	0
Interest expense									0	0	(1,572)
Total expenses									(38,997)	(22,978)	(19,931)
(Loss) income before equity in net (loss) income of subsidiaries and taxes									(6,166)	(9,551)	(6,869)
Equity in net income of subsidiaries									(878,178)	(255,217)	174,626
Income (loss) before taxes									(884,344)	(264,768)	167,757
Income tax (expense) benefit									0	0	0
Net income (loss)									(884,344)	(264,768)	167,757
Net (income) loss attributable to redeemable noncontrolling interests									0	0	0
Net income (loss) attributable to RenaissanceRe									(884,344)	(264,768)	167,757
Dividends on preference shares									0	0	0
Net income (loss) available (attributable) to RenaissanceRe common shareholders									$ (884,344)	$ (264,768)	$ 167,757