Noncontrolling Interests (Schedule Of Redeemable Noncontrolling Interest) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Activity in redeemable noncontrolling interest
Beginning balance			$ 1,045,964
Net income attributable to redeemable noncontrolling interest	$ 35,641	$ 31,153	110,867	$ 82,982
Ending balance	1,164,553		1,164,553		$ 1,045,964
DaVinciRe Holdings Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	953,443	879,266	930,955	1,037,306	1,037,306
Redemption of shares from redeemable noncontrolling interest	(400)	(1,007)	(92,204)	(209,718)
Sale of shares to redeemable noncontrolling interest	0	0	43,040	0
Net income attributable to redeemable noncontrolling interest	30,745	27,751	101,997	78,422
Ending balance	983,788	906,010	983,788	906,010	930,955
RenaissanceRe Medici Fund Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	168,960	109,546	115,009	94,402	94,402
Redemption of shares from redeemable noncontrolling interest	(14,389)	(1,910)	(21,729)	(19,017)	(20,100)
Sale of shares to redeemable noncontrolling interest	21,298	4,980	78,615	36,073	36,100
Net income attributable to redeemable noncontrolling interest	4,896	3,402	8,870	4,560
Ending balance	$ 180,765	$ 116,018	$ 180,765	$ 116,018	$ 115,009