Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues
Gross premiums written	$ 323,091	$ 430,224	$ 759,128	$ 862,133	$ 336,093	$ 369,642	$ 661,997	$ 643,578	$ 2,374,576	$ 2,011,310	$ 1,550,572
Net premiums written	219,499	284,222	519,916	511,675	236,651	266,820	508,677	404,035	1,535,312	1,416,183	1,068,236
(Increase) decrease in unearned premiums	132,402	62,299	(168,514)	(158,069)	124,924	95,568	(128,849)	(107,275)	(131,882)	(15,632)	(5,820)
Net premiums earned	351,901	346,521	351,402	353,606	361,575	362,388	379,828	296,760	1,403,430	1,400,551	1,062,416
Net investment income	47,316	51,423	54,124	28,863	45,918	28,338	38,604	39,707	181,726	152,567	124,316
Net foreign exchange (losses) gains	(5,420)	(5,986)	(690)	(1,692)	1,203	616	(1,740)	(3,130)	(13,788)	(3,051)	6,260
Equity in earnings (losses) of other ventures	4,960	(11,630)	6,022	1,611	3,296	5,730	6,160	5,295	963	20,481	26,075
Other income (loss)	5,177	2,268	2,654	4,079	8,200	2,306	1,427	1,539	14,178	13,472	(423)
Net realized and unrealized gains (losses) on investments	(49,967)	59,870	69,772	61,653	(42,817)	(41,138)	(26,712)	41,749	141,328	(68,918)	41,433
Total revenues	353,967	442,466	483,284	448,120	377,375	358,240	397,567	381,920	1,727,837	1,515,102	1,260,077
Expenses
Net claims and claim expenses incurred	123,901	112,575	167,750	126,605	102,013	100,028	169,344	76,853	530,831	448,238	197,947
Acquisition costs	74,146	80,580	69,005	65,592	55,399	78,126	61,666	43,401	289,323	238,592	144,476
Operational expenses	49,948	40,493	51,073	56,235	64,300	54,518	54,673	45,621	197,749	219,112	190,639
Corporate expenses	11,888	11,537	5,752	8,225	10,791	7,322	12,868	45,533	37,402	76,514	22,749
Interest expense	10,534	10,536	10,536	10,538	10,550	10,542	9,862	5,316	42,144	36,270	17,402
Total expenses	270,417	255,721	304,116	267,195	243,053	250,536	308,413	216,724	1,097,449	1,018,726	573,213
Income before taxes	83,550	186,745	179,168	180,925	134,322	107,704	89,154	165,196	630,388	496,376	686,864
Income tax (expense) benefit	7,700	1,316	(6,612)	(2,744)	(8,453)	4,573	1,842	47,904	(340)	45,866	(608)
Net income	91,250	188,061	172,556	178,181	125,869	112,277	90,996	213,100	630,048	542,242	686,256
Net income attributable to redeemable noncontrolling interests	(16,219)	(35,641)	(30,635)	(44,591)	(28,068)	(31,153)	(12,167)	(39,662)	(127,086)	(111,050)	(153,538)
Net income attributable to RenaissanceRe	75,031	152,420	141,921	133,590	97,801	81,124	78,829	173,438	502,962	431,192	532,718
Dividends on preference shares	(5,595)	(5,595)	(5,596)	(5,595)	(5,595)	(5,595)	(5,596)	(5,595)	(22,381)	(22,381)	(22,381)
Net income available to RenaissanceRe common shareholders	$ 69,436	$ 146,825	$ 136,325	$ 127,995	$ 92,206	$ 75,529	$ 73,233	$ 167,843	$ 480,581	$ 408,811	$ 510,337
Net income available to RenaissanceRe common shareholders per common share – basic, in dollars per share	$ 1.70	$ 3.58	$ 3.23	$ 2.97	$ 2.11	$ 1.68	$ 1.60	$ 4.18	$ 11.50	$ 9.36	$ 12.77
Net income available to RenaissanceRe common shareholders per common share – diluted, in dollars per share	$ 1.69	$ 3.56	$ 3.22	$ 2.95	$ 2.09	$ 1.66	$ 1.59	$ 4.14	$ 11.43	$ 9.28	$ 12.60
Average shares outstanding - basic (shares)	40,474	40,513	41,693	42,577	43,131	44,564	45,303	39,631	41,314	43,157	39,425
Average shares outstanding - diluted (shares)	40,707	40,733	41,885	42,912	43,513	44,913	45,657	40,021	41,559	43,526	39,968