v3.25.4
INVESTMENTS - Narrative (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
day
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Schedule of Investments [Line Items]      
Cash and investments at fair value on deposit with, or in trust accounts for the benefit of, various counterparties $ 8,600,000 $ 10,300,000  
Cash and investments at fair value on deposit with, or in trust accounts for the benefit of, U.S. state regulatory authorities 2,500,000 3,100,000  
Reverse repurchase agreements $ 59,200 169,400  
Number of business days required for redemption notice | day 4    
Net income $ 2,682,334 1,870,360 $ 2,561,132
Equity method investment, dividends and distributions $ 53,200 109,800 $ 41,400
RenaissanceRe Medici UCITS Fund      
Schedule of Investments [Line Items]      
Noncontrolling ownership percentage 34.30%    
Fair Value Measured at Net Asset Value Per Share      
Schedule of Investments [Line Items]      
Fair Value $ 2,775,499 $ 2,128,499  
RenaissanceRe Medici UCITS Fund      
Schedule of Investments [Line Items]      
Transfer in kind from existing investors 316,500    
RenaissanceRe Medici UCITS Fund | Primary Beneficiary      
Schedule of Investments [Line Items]      
Transfer in kind from existing investors 316,500    
Third-Party Investors | RenaissanceRe Medici UCITS Fund      
Schedule of Investments [Line Items]      
Noncontrolling interest, value subscribed 399,000    
RenaissanceRe Holdings Ltd. | RenaissanceRe Medici UCITS Fund | Primary Beneficiary      
Schedule of Investments [Line Items]      
Noncontrolling interest, value subscribed 140,000    
RenaissanceRe Medici UCITS Fund      
Schedule of Investments [Line Items]      
Net income 14,500    
Insurance-linked securities funds | Fair Value Measured at Net Asset Value Per Share      
Schedule of Investments [Line Items]      
Fair Value 154,500    
Insurance-linked securities funds | RenaissanceRe Medici UCITS Fund | Fair Value Measured at Net Asset Value Per Share      
Schedule of Investments [Line Items]      
Fair Value $ 449,900    
Minimum | Private credit funds      
Schedule of Investments [Line Items]      
Liquidating period 5 years    
Minimum | Private equity funds      
Schedule of Investments [Line Items]      
Liquidating period 5 years    
Minimum | Catastrophe bonds      
Schedule of Investments [Line Items]      
Maturity period 1 year    
Maximum | Private credit funds      
Schedule of Investments [Line Items]      
Liquidating period 10 years    
Maximum | Private equity funds      
Schedule of Investments [Line Items]      
Liquidating period 10 years    
Maximum | Catastrophe bonds      
Schedule of Investments [Line Items]      
Maturity period 5 years