SEGMENT REPORTING (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Gross premiums written	$ 1,618,443	$ 2,220,661	$ 7,060,325	$ 7,628,264
Net premiums written	1,421,260	1,821,711	5,880,766	5,850,544
Net premiums earned	1,755,876	1,767,021	5,221,688	4,709,829
Net claims and claim expenses incurred	861,576	1,967,931	2,593,987	3,515,903
Acquisition expenses	425,745	417,644	1,280,547	1,155,389
Operational expenses	82,751	64,560	240,716	204,987
Underwriting income (loss)	385,804	(683,114)	1,106,438	(166,450)
Net investment income	329,108	157,793	876,148	348,695
Net foreign exchange gains (losses)	(25,886)	(1,383)	(53,877)	(67,690)
Equity in earnings of other ventures	10,842	1,739	28,072	2,732
Other income (loss)	(5,866)	2,834	(6,296)	4,950
Net realized and unrealized gains (losses) on investments	(228,087)	(641,500)	(171,417)	(1,968,624)
Corporate expenses	(17,143)	(10,384)	(53,357)	(35,238)
Interest expense	(22,951)	(12,101)	(49,980)	(35,951)
Income (loss) before taxes	425,821	(1,186,116)	1,675,731	(1,917,576)
Income tax benefit (expense)	(9,295)	(2,814)	(44,139)	64,427
Net (income) loss attributable to redeemable noncontrolling interests	(213,695)	372,429	(655,986)	335,010
Dividends on preference shares	(8,843)	(8,843)	(26,531)	(26,531)
Net income (loss) available (attributable) to RenaissanceRe common shareholders	193,988	(825,344)	949,075	(1,544,670)
Net income (loss) available (attributable) to RenaissanceRe common shareholders, diluted	193,988	(825,344)	949,075	(1,544,670)
Net claims and claim expenses incurred – current accident year	1,019,523	1,999,837	2,888,784	3,608,599
Net claims and claim expenses incurred – prior accident years	(157,947)	(31,906)	(294,797)	(92,696)
Total net incurred	$ 861,576	$ 1,967,931	$ 2,593,987	$ 3,515,903
Net claims and claim expense ratio – current accident year	58.10%	113.20%	55.30%	76.60%
Net claims and claim expense ratio – prior accident years	(9.00%)	(1.80%)	(5.60%)	(1.90%)
Net claims and claim expense ratio – calendar year	49.10%	111.40%	49.70%	74.70%
Underwriting expense ratio	28.90%	27.30%	29.10%	28.90%
Combined ratio	78.00%	138.70%	78.80%	103.60%
Other
Segment Reporting Information [Line Items]
Gross premiums written	$ 0	$ 0	$ 0	$ 0
Net premiums written	0	0	0	0
Net premiums earned	0	0	0	0
Net claims and claim expenses incurred	0	0	0	0
Acquisition expenses	0	0	0	0
Operational expenses	0	0	0	0
Underwriting income (loss)	0	0	0	0
Net investment income	329,108	157,793	876,148	348,695
Net foreign exchange gains (losses)	(25,886)	(1,383)	(53,877)	(67,690)
Equity in earnings of other ventures	10,842	1,739	28,072	2,732
Other income (loss)	(5,866)	2,834	(6,296)	4,950
Net realized and unrealized gains (losses) on investments	(228,087)	(641,500)	(171,417)	(1,968,624)
Corporate expenses	(17,143)	(10,384)	(53,357)	(35,238)
Interest expense	(22,951)	(12,101)	(49,980)	(35,951)
Income tax benefit (expense)	(9,295)	(2,814)	(44,139)	64,427
Net (income) loss attributable to redeemable noncontrolling interests	(213,695)	372,429	(655,986)	335,010
Dividends on preference shares	(8,843)	(8,843)	(26,531)	(26,531)
Net claims and claim expenses incurred – current accident year	0	0	0	0
Net claims and claim expenses incurred – prior accident years	0	0	0	0
Total net incurred	0	0	0	0
Property
Segment Reporting Information [Line Items]
Net claims and claim expenses incurred – prior accident years			(257,209)	(76,069)
Property | Operating Segments
Segment Reporting Information [Line Items]
Gross premiums written	511,012	800,330	3,217,817	3,362,159
Net premiums written	444,872	696,520	2,609,356	2,474,661
Net premiums earned	760,365	839,817	2,206,471	2,081,989
Net claims and claim expenses incurred	206,361	1,372,583	675,963	1,804,268
Acquisition expenses	143,348	141,675	429,273	406,338
Operational expenses	54,624	48,158	165,514	144,717
Underwriting income (loss)	356,032	(722,599)	935,721	(273,334)
Net claims and claim expenses incurred – current accident year	350,238	1,396,842	933,172	1,880,337
Net claims and claim expenses incurred – prior accident years	(143,877)	(24,259)	(257,209)	(76,069)
Total net incurred	$ 206,361	$ 1,372,583	$ 675,963	$ 1,804,268
Net claims and claim expense ratio – current accident year	46.10%	166.30%	42.30%	90.30%
Net claims and claim expense ratio – prior accident years	(19.00%)	(2.90%)	(11.70%)	(3.60%)
Net claims and claim expense ratio – calendar year	27.10%	163.40%	30.60%	86.70%
Underwriting expense ratio	26.10%	22.60%	27.00%	26.40%
Combined ratio	53.20%	186.00%	57.60%	113.10%
Casualty and Specialty
Segment Reporting Information [Line Items]
Net claims and claim expenses incurred – prior accident years			$ (37,588)	$ (16,627)
Casualty and Specialty | Operating Segments
Segment Reporting Information [Line Items]
Gross premiums written	$ 1,107,431	$ 1,420,331	3,842,508	4,266,105
Net premiums written	976,388	1,125,191	3,271,410	3,375,883
Net premiums earned	995,511	927,204	3,015,217	2,627,840
Net claims and claim expenses incurred	655,215	595,348	1,918,024	1,711,635
Acquisition expenses	282,397	275,969	851,274	749,051
Operational expenses	28,127	16,402	75,202	60,270
Underwriting income (loss)	29,772	39,485	170,717	106,884
Net claims and claim expenses incurred – current accident year	669,285	602,995	1,955,612	1,728,262
Net claims and claim expenses incurred – prior accident years	(14,070)	(7,647)	(37,588)	(16,627)
Total net incurred	$ 655,215	$ 595,348	$ 1,918,024	$ 1,711,635
Net claims and claim expense ratio – current accident year	67.20%	65.00%	64.90%	65.80%
Net claims and claim expense ratio – prior accident years	(1.40%)	(0.80%)	(1.30%)	(0.70%)
Net claims and claim expense ratio – calendar year	65.80%	64.20%	63.60%	65.10%
Underwriting expense ratio	31.20%	31.50%	30.70%	30.80%
Combined ratio	97.00%	95.70%	94.30%	95.90%