Subsequent Events (Details) - USD ($) $ / shares in Units, shares in Thousands			1 Months Ended		2 Months Ended	12 Months Ended
	Feb. 01, 2017	Jan. 01, 2017	Feb. 22, 2017	Jan. 31, 2017	Feb. 17, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Aug. 02, 2016
Subsequent Event [Line Items]
Investment in variable interest entity						$ 0	$ 0	$ 0
Common shares
Subsequent Event [Line Items]
Repurchase of shares (in shares)						2,700
Common shares repurchased during period, Aggregate value						$ 309,400,000
Common shares repurchased during period, Average cost per share (in dollars per share)						$ 112.87
Share repurchase program, Authorized aggregate amount									$ 500,000,000
Subsequent Event | Common shares
Subsequent Event [Line Items]
Repurchase of shares (in shares)					281
Common shares repurchased during period, Aggregate value					$ 40,000,000
Common shares repurchased during period, Average cost per share (in dollars per share)					$ 142.40
Share repurchase program, Authorized aggregate amount			$ 500,000,000
DaVinciRe Holdings Ltd.
Subsequent Event [Line Items]
Redeemable noncontrolling interest, ownership percentage						24.00%	26.30%
Noncontrolling interest, value subscribed						$ 43,040,000	$ 0
Redemption of shares from redeemable noncontrolling interests						98,285,000	212,750,000
DaVinciRe Holdings Ltd. | Subsequent Event
Subsequent Event [Line Items]
Redeemable noncontrolling interest, redemptions				$ 75,000,000
Redeemable noncontrolling interest, reserve holdback				15,000,000
Redeemable noncontrolling interest, sale of interest				24,000,000
Redeemable noncontrolling interest, ownership percentage		22.60%
Upsilon RFO Re Ltd. | Primary Beneficiary | Non-voting preference shares
Subsequent Event [Line Items]
Non-voting preference shares issued to third parties						166,600,000	153,700,000
Investment in variable interest entity						$ 55,200,000	$ 42,500,000
Upsilon RFO Re Ltd. | Subsequent Event | Primary Beneficiary
Subsequent Event [Line Items]
Capital distribution payable				41,800,000
Variable interest entity, ownership percentage	16.60%
Upsilon RFO Re Ltd. | Subsequent Event | Primary Beneficiary | Non-voting preference shares
Subsequent Event [Line Items]
Non-voting preference shares issued to third parties			$ 7,500,000	134,100,000
Fibonacci Reinsurance Ltd. | Subsequent Event | Primary Beneficiary
Subsequent Event [Line Items]
Non-voting preference shares issued to third parties		$ 140,000,000
Variable interest entity, ownership percentage	7.20%
RenaissanceRe Medici Fund Ltd.
Subsequent Event [Line Items]
Redeemable noncontrolling interest, ownership percentage						36.50%	46.10%
Noncontrolling interest, value subscribed						$ 79,518,000	$ 36,073,000
Redemption of shares from redeemable noncontrolling interests						$ 21,729,000	$ 20,117,000
RenaissanceRe Medici Fund Ltd. | Subsequent Event
Subsequent Event [Line Items]
Redeemable noncontrolling interest, ownership percentage	33.70%
RenaissanceRe Holdings Ltd. | Upsilon RFO Re Ltd. | Primary Beneficiary
Subsequent Event [Line Items]
Variable interest entity, ownership percentage						28.80%	21.70%
RenaissanceRe Holdings Ltd. | Upsilon RFO Re Ltd. | Subsequent Event | Primary Beneficiary
Subsequent Event [Line Items]
Capital distribution payable				9,500,000
RenaissanceRe Holdings Ltd. | Upsilon RFO Re Ltd. | Subsequent Event | Primary Beneficiary | Non-voting preference shares
Subsequent Event [Line Items]
Investment in variable interest entity				$ 9,500,000
RenaissanceRe Holdings Ltd. | RenaissanceRe Medici Fund Ltd. | Subsequent Event
Subsequent Event [Line Items]
Noncontrolling interest, value subscribed					$ 10,200,000
Redemption of shares from redeemable noncontrolling interests					10,000,000
Third-Party Investor [Member] | RenaissanceRe Medici Fund Ltd. | Subsequent Event
Subsequent Event [Line Items]
Noncontrolling interest, value subscribed					25,900,000
Redemption of shares from redeemable noncontrolling interests					$ 1,500,000