Noncontrolling Interests (Schedule of Redeemable Noncontrolling Interest) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Activity in redeemable noncontrolling interest
Beginning balance	$ 3,388,319
Net loss attributable to redeemable noncontrolling interest	(46,850)	$ 98,091
Ending balance	3,409,570
DaVinciRe Holdings Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	1,560,693	1,435,581
Redemption of shares from redeemable noncontrolling interest, net of adjustments	(155,971)	2,607
Sale of shares to redeemable noncontrolling interests	250,000
Net loss attributable to redeemable noncontrolling interest	(39,934)	84,906
Ending balance	1,555,714	1,533,085
DaVinciRe Holdings Ltd. \| Third-Party Investors And RenaissanceRe
Activity in redeemable noncontrolling interest
Sale of shares to redeemable noncontrolling interests	190,926	9,991
Medici
Activity in redeemable noncontrolling interest
Beginning balance	717,999	632,112
Redemption of shares from redeemable noncontrolling interest, net of adjustments	(7,699)	(4,764)
Sale of shares to redeemable noncontrolling interests	40,845	54,613
Net loss attributable to redeemable noncontrolling interest	(13,443)	(4,678)
Ending balance	737,702	677,283
Vermeer Reinsurance Ltd.
Activity in redeemable noncontrolling interest
Beginning balance	1,109,627	1,003,615
Net loss attributable to redeemable noncontrolling interest	6,527	17,863
Ending balance	$ 1,116,154	$ 1,021,478

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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).

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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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