Consolidated Statements Of Comprehensive (Loss) Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Comprehensive (loss) income
Net (loss) income	$ (354,671)	$ 630,048	$ 542,242
Change in net unrealized gains on investments	(909)	(975)	(1,308)
Comprehensive (loss) income	(355,580)	629,073	540,934
Net loss (income) attributable to redeemable noncontrolling interests	132,282	(127,086)	(111,050)
Comprehensive (loss) income attributable to redeemable noncontrolling interests	132,282	(127,086)	(111,050)
Comprehensive (loss) income attributable to RenaissanceRe	(223,298)	501,987	429,884
Disclosure regarding net unrealized gains
Total net realized and unrealized holding (losses) gains on investments	(909)	403	(982)
Net realized gains on fixed maturity investments available for sale	0	(1,378)	(326)
Change in net unrealized gains on investments	$ (909)	$ (975)	$ (1,308)