Acquisition of Tokio Millennium Re (Schedule of Purchase Price) (Details) - TMR - USD ($) $ / shares in Units, $ in Thousands	Mar. 22, 2019	Mar. 15, 2019
Business Acquisition [Line Items]
Special Dividend paid to common shareholders of Tokio and holders of Tokio equity awards	$ 500,000
Shares issued (in shares)	1,739,071
Common share price of RenaissanceRe (in dollars per share)	$ 143.75	$ 143.7539
Market value of RenaissanceRe common shares issued by RenaissanceRe to Tokio	$ 249,998
Cash consideration paid by RenaissanceRe as acquisition consideration	813,595
Total purchase price	1,563,593
Less: Special Dividend paid to Tokio	(500,000)
Net purchase price	$ 1,063,593
Common share price, trading volume, term		30 days