Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows provided by operating activities
Net income (loss)	$ 950,267	$ 268,917	$ (354,671)
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Amortization, accretion and depreciation	(58,964)	123	31,242
Equity in undistributed (earnings) losses of other ventures	(762)	(3,772)	6,295
Net realized and unrealized (gains) losses on investments	(414,483)	175,069	(135,822)
Net unrealized (gains) losses included in net investment income	(12,221)	8,309	(24,737)
Change in:
Premiums receivable	(424,973)	(232,566)	(317,299)
Prepaid reinsurance premiums	(11,798)	(82,639)	(92,286)
Reinsurance recoverable	129,665	(785,591)	(1,307,066)
Deferred acquisition costs	118,676	(50,110)	(91,226)
Reserve for claims and claim expenses	900,562	995,863	2,232,114
Unearned premiums	51,343	238,412	246,036
Reinsurance balances payable	658,532	912,966	315,107
Other	251,351	(223,280)	518,100
Net cash provided by operating activities	2,137,195	1,221,701	1,025,787
Cash flows used in investing activities
Proceeds from sales and maturities of fixed maturity investments trading	17,313,940	11,585,576	9,490,669
Purchases of fixed maturity investments trading	(17,919,343)	(12,489,972)	(10,093,532)
Net (purchases) sales of equity investments trading	(7,841)	14,156	115,837
Net (purchases) sales of short term investments	(1,900,741)	(1,436,389)	364,011
Net purchases of other investments	(202,878)	(199,475)	(19,419)
Net purchases of investments in other ventures	(2,717)	(21,473)	0
Return of investment from investment in other ventures	11,250	8,464	20,000
Net (purchases) sales of other assets	(4,108)	2,500	0
Net purchase of TMR	(276,206)	0	0
Net cash used in investing activities	(2,988,644)	(2,536,613)	(122,434)
Cash flows provided by financing activities
Dividends paid – RenaissanceRe common shares	(59,368)	(52,841)	(51,370)
Dividends paid – preference shares	(36,756)	(30,088)	(22,381)
RenaissanceRe common share repurchases	0	0	(188,591)
RenaissanceRe common share issuance	0	250,000	0
Issuance of debt, net of expenses	396,411	0	295,866
Repayment of debt	0	0	(250,000)
Issuance of preference shares, net of expenses	0	241,448	0
Net third-party redeemable noncontrolling interest share transactions	827,083	665,683	260,475
Taxes paid on withholding shares	(7,253)	(7,862)	(15,139)
Net cash provided by financing activities	1,120,117	1,066,340	28,860
Effect of exchange rate changes on foreign currency cash	2,478	(5,098)	8,222
Net increase (decrease) in cash and cash equivalents	271,146	(253,670)	940,435
Cash and cash equivalents, beginning of year	1,107,922	1,361,592	421,157
Cash and cash equivalents, end of year	1,379,068	1,107,922	1,361,592
Supplemental Cash Flow Information
Income taxes paid	9,749	341	343
Interest paid	$ 53,220	$ 45,623	$ 44,171