Noncontrolling Interests (Schedule Of Redeemable Noncontrolling Interest) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Activity in redeemable noncontrolling interest
Beginning balance	$ 1,175,594
Net (loss) income attributable to redeemable noncontrolling interest	(132,282)	$ 127,086	$ 111,050
Ending balance	1,296,506	1,175,594
DaVinciRe Holdings Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	994,458	930,955
Redemption of shares from redeemable noncontrolling interest	(80,058)	(98,285)
Sale of shares to redeemable noncontrolling interest	232,119	43,040
Net (loss) income attributable to redeemable noncontrolling interest	(134,860)	118,748	106,399
Ending balance	1,011,659	994,458	930,955
RenaissanceRe Medici Fund Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	181,136	115,009
Redemption of shares from redeemable noncontrolling interest	(48,049)	(21,729)
Sale of shares to redeemable noncontrolling interest	149,182	79,518
Net (loss) income attributable to redeemable noncontrolling interest	2,578	8,338	4,651
Ending balance	$ 284,847	$ 181,136	$ 115,009

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

+ References

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-Publisher FASB
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- Definition

Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

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Amount of increase in noncontrolling interest from subsidiary issuance of equity interests to noncontrolling interest holders.

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As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

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