Acquisition of Tokio Millennium Re (Schedule of Fair Value of Net Assets Acquired and Liabilities Assumed) (Details) - TMR - USD ($) $ in Thousands	Mar. 22, 2019	Dec. 31, 2019
Business Acquisition [Line Items]
Shareholders’ equity of TMR at March 22, 2019	$ 1,032,961
Adjustments for fair value, by applicable balance sheet caption:
Net deferred acquisition costs and value of business acquired	(56,788)
Net reserve for claims and claim expenses	67,782
Goodwill and intangible assets at March 22, 2019 of TMR	(6,569)
Total adjustments for fair value by applicable balance sheet caption before tax impact	4,425
Other assets - net deferred tax liability related to fair value adjustments and value of business acquired	(2,606)
Total adjustments for fair value by applicable balance sheet caption, net of tax	1,819
Adjustments for fair value of the identifiable intangible assets:
Identifiable intangible assets before tax impact	18,000	$ 17,190
Other assets - deferred tax liability on identifiable intangible assets	(2,281)
Total adjustments for fair value of the identifiable intangible assets and value of business acquired, net of tax	15,719
Total adjustments for fair value by applicable balance sheet caption, identifiable intangible assets and value of business acquired, net of tax	17,538
Shareholders’ equity of TMR at fair value	1,050,499
Total net purchase price paid by RenaissanceRe	1,063,593
Excess purchase price over the fair value of net assets acquired assigned to goodwill	13,094
Insurance licenses
Adjustments for fair value of the identifiable intangible assets:
Identifiable indefinite lived intangible assets (insurance licenses)	6,800
Top Broker Relationships and Renewal Rights
Adjustments for fair value of the identifiable intangible assets:
Identifiable finite lived intangible assets (top broker relationships and renewal rights)	$ 11,200