Condensed Consolidating Financial Information Provided in Connection with Outstanding Debt of Subsidiaries (Condensed Consolidating Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Total investments	$ 17,368,789	$ 11,885,747
Cash and cash equivalents	1,379,068	1,107,922
Investments in subsidiaries	0	0
Due from subsidiaries and affiliates	0	0
Premiums receivable	2,599,896	1,537,188
Prepaid reinsurance premiums	767,781	616,185
Reinsurance recoverable	2,791,297	2,372,221	$ 1,586,630
Accrued investment income	72,461	51,311
Deferred acquisition costs and value of business acquired	663,991	476,661
Receivable for investments sold	78,369	256,416
Other assets	346,216	135,127
Goodwill and other intangible assets	262,226	237,418
Total assets	26,330,094	18,676,196
Liabilities
Reserve for claims and claim expenses (Note 8)	9,384,349	6,076,271	5,080,408
Unearned premiums	2,530,975	1,716,021
Debt (Note 9)	1,384,105	991,127
Amounts due to subsidiaries and affiliates	0	0
Reinsurance balances payable	2,830,691	1,902,056
Payable for investments purchased	225,275	380,332
Other liabilities	932,024	513,609
Total liabilities	17,287,419	11,579,416
Redeemable noncontrolling interests	3,071,308	2,051,700
Shareholders’ Equity
Total shareholders’ equity	5,971,367	5,045,080	$ 4,391,375
Total liabilities, noncontrolling interests and shareholders’ equity	26,330,094	18,676,196
RenaissanceRe Holdings Ltd. (Parent Guarantor)
Assets
Cash and cash equivalents	26,460	3,534
Investments in subsidiaries	5,204,260	4,414,475
Accrued investment income	0	1,046
Receivable for investments sold	173	203
Other assets	847,406	458,842
Goodwill and other intangible assets	116,212	120,476
Total assets	6,395,687	5,368,975
Liabilities
Amounts due to subsidiaries and affiliates	6,708	6,453
Other liabilities	26,137	17,442
Total liabilities	424,320	323,895
Shareholders’ Equity
Total shareholders’ equity	5,971,367	5,045,080
Total liabilities, noncontrolling interests and shareholders’ equity	6,395,687	5,368,975
Reportable Legal Entities | RenaissanceRe Holdings Ltd. (Parent Guarantor)
Assets
Total investments	190,451	313,360
Cash and cash equivalents	26,460	3,534
Investments in subsidiaries	5,204,260	4,414,475
Due from subsidiaries and affiliates	10,725	57,039
Premiums receivable	0	0
Prepaid reinsurance premiums	0	0
Reinsurance recoverable	0	0
Accrued investment income	0	1,046
Deferred acquisition costs and value of business acquired	0	0
Receivable for investments sold	173	203
Other assets	847,406	458,842
Goodwill and other intangible assets	116,212	120,476
Total assets	6,395,687	5,368,975
Liabilities
Reserve for claims and claim expenses (Note 8)	0	0
Unearned premiums	0	0
Debt (Note 9)	391,475	300,000
Amounts due to subsidiaries and affiliates	6,708	6,453
Reinsurance balances payable	0	0
Payable for investments purchased	0	0
Other liabilities	26,137	17,442
Total liabilities	424,320	323,895
Redeemable noncontrolling interests	0	0
Shareholders’ Equity
Total shareholders’ equity	5,971,367	5,045,080
Total liabilities, noncontrolling interests and shareholders’ equity	6,395,687	5,368,975
Reportable Legal Entities | Other RenaissanceRe Holdings Ltd. Subsidiaries And Eliminations (Non-Guarantor Subsidiaries)
Assets
Total investments	16,766,409	11,465,660
Cash and cash equivalents	1,334,437	1,091,434
Investments in subsidiaries	0	0
Due from subsidiaries and affiliates	0	0
Premiums receivable	2,599,896	1,537,188
Prepaid reinsurance premiums	767,781	616,185
Reinsurance recoverable	2,791,297	2,372,221
Accrued investment income	71,020	49,828
Deferred acquisition costs and value of business acquired	663,991	476,661
Receivable for investments sold	78,196	232,328
Other assets	301,578	(1,403,636)
Goodwill and other intangible assets	146,014	116,942
Total assets	25,520,619	16,554,811
Liabilities
Reserve for claims and claim expenses (Note 8)	9,384,349	6,076,271
Unearned premiums	2,530,975	1,716,021
Debt (Note 9)	148,349	148,041
Amounts due to subsidiaries and affiliates	0	0
Reinsurance balances payable	2,830,691	1,902,056
Payable for investments purchased	225,275	380,308
Other liabilities	899,682	482,422
Total liabilities	16,019,321	10,705,119
Redeemable noncontrolling interests	3,071,308	2,051,700
Shareholders’ Equity
Total shareholders’ equity	6,429,990	3,797,992
Total liabilities, noncontrolling interests and shareholders’ equity	25,520,619	16,554,811
Reportable Legal Entities | RenRe North America Holdings Inc. (Subsidiary Issuer)
Assets
Total investments	123,792	77,842
Cash and cash equivalents	9,440	3,350
Investments in subsidiaries	48,247	58,458
Due from subsidiaries and affiliates	101,579	101,579
Premiums receivable	0	0
Prepaid reinsurance premiums	0	0
Reinsurance recoverable	0	0
Accrued investment income	270	310
Deferred acquisition costs and value of business acquired	0	0
Receivable for investments sold	0	23,885
Other assets	10,978	22,571
Goodwill and other intangible assets	0	0
Total assets	294,306	287,995
Liabilities
Reserve for claims and claim expenses (Note 8)	0	0
Unearned premiums	0	0
Debt (Note 9)	0	0
Amounts due to subsidiaries and affiliates	51	217
Reinsurance balances payable	0	0
Payable for investments purchased	0	24
Other liabilities	278	5,362
Total liabilities	329	5,603
Redeemable noncontrolling interests	0	0
Shareholders’ Equity
Total shareholders’ equity	293,977	282,392
Total liabilities, noncontrolling interests and shareholders’ equity	294,306	287,995
Reportable Legal Entities | RenaissanceRe Finance, Inc. (Subsidiary Issuer)
Assets
Total investments	288,137	28,885
Cash and cash equivalents	8,731	9,604
Investments in subsidiaries	1,426,838	1,215,663
Due from subsidiaries and affiliates	0	0
Premiums receivable	0	0
Prepaid reinsurance premiums	0	0
Reinsurance recoverable	0	0
Accrued investment income	1,171	127
Deferred acquisition costs and value of business acquired	0	0
Receivable for investments sold	0	0
Other assets	12,211	313,636
Goodwill and other intangible assets	0	0
Total assets	1,737,088	1,567,915
Liabilities
Reserve for claims and claim expenses (Note 8)	0	0
Unearned premiums	0	0
Debt (Note 9)	970,255	843,086
Amounts due to subsidiaries and affiliates	102,493	102,243
Reinsurance balances payable	0	0
Payable for investments purchased	0	0
Other liabilities	14,162	13,918
Total liabilities	1,086,910	959,247
Redeemable noncontrolling interests	0	0
Shareholders’ Equity
Total shareholders’ equity	650,178	608,668
Total liabilities, noncontrolling interests and shareholders’ equity	1,737,088	1,567,915
Consolidating Adjustments
Assets
Total investments	0	0
Cash and cash equivalents	0	0
Investments in subsidiaries	(6,679,345)	(5,688,596)
Due from subsidiaries and affiliates	(112,304)	(158,618)
Premiums receivable	0	0
Prepaid reinsurance premiums	0	0
Reinsurance recoverable	0	0
Accrued investment income	0	0
Deferred acquisition costs and value of business acquired	0	0
Receivable for investments sold	0	0
Other assets	(825,957)	743,714
Goodwill and other intangible assets	0	0
Total assets	(7,617,606)	(5,103,500)
Liabilities
Reserve for claims and claim expenses (Note 8)	0	0
Unearned premiums	0	0
Debt (Note 9)	(125,974)	(300,000)
Amounts due to subsidiaries and affiliates	(109,252)	(108,913)
Reinsurance balances payable	0	0
Payable for investments purchased	0	0
Other liabilities	(8,235)	(5,535)
Total liabilities	(243,461)	(414,448)
Redeemable noncontrolling interests	0	0
Shareholders’ Equity
Total shareholders’ equity	(7,374,145)	(4,689,052)
Total liabilities, noncontrolling interests and shareholders’ equity	$ (7,617,606)	$ (5,103,500)