Acquisition of Platinum Narrative (Details) - USD ($)								3 Months Ended	12 Months Ended
	Dec. 30, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Mar. 15, 2016	Mar. 24, 2015	Mar. 02, 2015	Mar. 01, 2015	Dec. 31, 2016	Dec. 31, 2015
Common Shares
Business Acquisition [Line Items]
Dividends per common share, in usd per share	$ 0.31	$ 0.31	$ 0.31	$ 0.31	$ 0.31
Platinum Underwriters Holdings, Ltd.
Business Acquisition [Line Items]
Dividends per common share, in usd per share								$ 10
Dividends paid, value							$ 253,203,000	$ 253,203,000
RenaissanceRe Finance, Inc. | 3.700% Senior Notes Due April 1, 2025
Business Acquisition [Line Items]
Debt instrument, face amount						$ 300,000,000
Senior notes interest rate						3.70%
Debt instrument maturity date						April 1, 2025
Platinum Underwriters Holdings, Ltd.
Business Acquisition [Line Items]
Percent acquired							100.00%
Share price, in usd per share							$ 76
Aggregate consideration transferred							$ 1,932,405,000
Cash consideration paid by RenaissanceRe to common shareholders of Platinum and holders of Platinum equity awards							1,160,000,000
Funds available to fund acquisition							604,400,000
Transaction-related costs									$ 2,100,000	$ 53,500,000
Goodwill							191,729,000
Finite lived intangible assets acquired							$ 75,200,000
Weighted average useful life							8 years
Indefinite lived intangible assets acquired							$ 8,400,000
Adjustment to deferred tax asset							29,069,000
Other liabilities - deferred tax liability on identifiable intangible assets							$ (13,115,000)
Platinum Underwriters Holdings, Ltd. | Bridge Loan
Business Acquisition [Line Items]
Short-term debt						$ 300,000,000
Platinum Underwriters Holdings, Ltd. | Common Shares
Business Acquisition [Line Items]
Share price, in usd per share							$ 35.96
Shares issued							7,434,561
Shares issued, value							$ 761,819,000
Cash consideration paid by RenaissanceRe to common shareholders of Platinum and holders of Platinum equity awards							$ 904,433,000