Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows provided by operating activities
Net income (loss)	$ 268,917	$ (354,671)	$ 630,048
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Amortization, accretion and depreciation	123	31,242	29,304
Equity in undistributed (earnings) losses of other ventures	(3,772)	6,295	5,504
Net realized and unrealized losses (gains) on investments	175,069	(135,822)	(141,328)
Net unrealized losses (gains) included in net investment income	8,309	(24,737)	(11,542)
Change in:
Premiums receivable	(232,566)	(317,299)	(209,314)
Prepaid reinsurance premiums	(82,639)	(92,286)	(210,589)
Reinsurance recoverable	(785,591)	(1,307,066)	(145,038)
Deferred acquisition costs	(50,110)	(91,226)	(135,945)
Reserve for claims and claim expenses	995,863	2,232,114	81,249
Unearned premiums	238,412	246,036	342,471
Reinsurance balances payable	912,966	315,107	150,009
Other	(223,280)	518,100	99,943
Net cash provided by operating activities	1,221,701	1,025,787	484,772
Cash flows used in investing activities
Proceeds from sales and maturities of fixed maturity investments trading	11,585,576	9,490,669	8,102,514
Purchases of fixed maturity investments trading	(12,489,972)	(10,093,532)	(8,282,720)
Proceeds from sales and maturities of fixed maturity investments available for sale	0	0	17,692
Net sales of equity investments trading	14,156	115,837	184,788
Net (purchases) sales of short term investments	(1,436,389)	364,011	(118,617)
Net purchases of other investments	(199,475)	(19,419)	(68,589)
Net purchases of investments in other ventures	(21,473)	0	0
Return of investment from investment in other ventures	8,464	20,000	0
Net sales of other assets	2,500	0	400
Net cash used in investing activities	(2,536,613)	(122,434)	(164,532)
Cash flows provided by (used in) financing activities
Dividends paid – RenaissanceRe common shares	(52,841)	(51,370)	(51,583)
Dividends paid – preference shares	(30,088)	(22,381)	(22,381)
RenaissanceRe common share repurchases	0	(188,591)	(309,434)
RenaissanceRe common share issuance	250,000	0	0
Issuance of debt, net of expenses	0	295,866	0
Repayment of debt	0	(250,000)	0
Net third party redeemable noncontrolling interest share transactions	665,683	260,475	(2,990)
Taxes paid on withholding shares	(7,862)	(15,139)	(14,943)
Net cash provided by (used in) financing activities	1,066,340	28,860	(401,331)
Effect of exchange rate changes on foreign currency cash	(5,098)	8,222	(4,637)
Net (decrease) increase in cash and cash equivalents	(253,670)	940,435	(85,728)
Cash and cash equivalents, beginning of period	1,361,592	421,157	506,885
Cash and cash equivalents, end of period	1,107,922	1,361,592	421,157
Supplemental Cash Flow Information
Income taxes paid (refunded)	341	343	(1,118)
Interest paid	$ 50,775	$ 44,171	$ 53,977