v3.25.4
VARIABLE INTEREST ENTITIES (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
account
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Variable Interest Entity [Line Items]      
Number of segregated accounts | account 4    
Assets $ 53,800,390 $ 50,707,550  
Liabilities 34,589,641 33,155,789  
Investments 36,073,209 32,639,456  
Other assets 328,087 444,037  
Reserve for claims and claim expenses 22,302,345 21,303,491 $ 20,486,869
Other liabilities 856,302 1,060,129  
Investments in other ventures, under equity method (Note 5) 121,871 102,770  
Ceded premiums written 1,868,220 1,780,850 1,394,553
Ceded premiums earned 1,762,771 1,817,302 1,614,432
Primary Beneficiary | Upsilon RFO Re Ltd.      
Variable Interest Entity [Line Items]      
Assets 653,000 1,200,000  
Liabilities 652,100 1,200,000  
Investments 526,800 908,600  
Other assets 126,200 270,000  
Reserve for claims and claim expenses 305,800 637,000  
Other liabilities 346,300 540,700  
Net assets 32,700 60,500  
Primary Beneficiary | Investors of Upsilon RFO Diversified I, II and III | Upsilon RFO Re Ltd.      
Variable Interest Entity [Line Items]      
Payments of capital distributions 287,100 397,600  
Net assets 264,800 282,200  
Primary Beneficiary | RenaissanceRe Holdings Ltd. | Upsilon RFO Re Ltd.      
Variable Interest Entity [Line Items]      
Payments of capital distributions $ 34,500 $ 59,800  
Variable interest entity, ownership percentage 12.70% 12.70%  
Primary Beneficiary | Investors of Upsilon RFO Diversified IV | Upsilon RFO Re Ltd.      
Variable Interest Entity [Line Items]      
Payments of capital distributions $ 36,900 $ 16,300  
Not Primary Beneficiary | RenaissanceRe Upsilon Diversified Fund      
Variable Interest Entity [Line Items]      
Investments in other ventures, under equity method (Note 5) 400 500  
Not Primary Beneficiary | NOC1      
Variable Interest Entity [Line Items]      
Investments in other ventures, under equity method (Note 5) 1,900 1,700  
Not Primary Beneficiary | AlphaCat Managers Ltd      
Variable Interest Entity [Line Items]      
Investments in other ventures, under equity method (Note 5) 2,200 3,600  
Not Primary Beneficiary | RenaissanceRe Upsilon Diversified Fund      
Variable Interest Entity [Line Items]      
Assets 278,400 440,600  
Liabilities 42,600 140,900  
Not Primary Beneficiary | RenaissanceRe Upsilon Diversified Fund | Upsilon RFO Re Ltd.      
Variable Interest Entity [Line Items]      
Investment owned, fair value 254,700 304,000  
Not Primary Beneficiary | NOC1      
Variable Interest Entity [Line Items]      
Assets 192,700 173,400  
Liabilities 500 2,200  
Not Primary Beneficiary | Stratos      
Variable Interest Entity [Line Items]      
Assets 261,900    
Liabilities 200    
Not Primary Beneficiary | Mona Lisa Re      
Variable Interest Entity [Line Items]      
Assets 1,100,000 936,100  
Liabilities 1,100,000 936,100  
Not Primary Beneficiary | Mona Lisa Re | Other Investments      
Variable Interest Entity [Line Items]      
Investment in participating notes 3,400 7,000  
Not Primary Beneficiary | Tailwind Re Ltd      
Variable Interest Entity [Line Items]      
Assets   416,800  
Liabilities   416,800  
Not Primary Beneficiary | AlphaCat Managers Ltd      
Variable Interest Entity [Line Items]      
Assets 1,100,000 3,000,000  
Liabilities 500,000 1,300,000  
Not Primary Beneficiary | RenaissanceRe Holdings Ltd. | RenaissanceRe Upsilon Diversified Fund      
Variable Interest Entity [Line Items]      
Payments of capital distributions 400 500  
Not Primary Beneficiary | RenaissanceRe Holdings Ltd. | NOC1 | Preference shares      
Variable Interest Entity [Line Items]      
Investment in variable interest entity   200  
Redemption of preference shares   500  
Not Primary Beneficiary | RenaissanceRe Holdings Ltd. | Tailwind Re Ltd      
Variable Interest Entity [Line Items]      
Ceded premiums written   42,700  
Ceded premiums earned   42,700  
Not Primary Beneficiary | Investors of Upsilon RFO Diversified IV | Upsilon RFO Re Ltd.      
Variable Interest Entity [Line Items]      
Net assets 101,800 115,900  
Not Primary Beneficiary | Investor | RenaissanceRe Upsilon Diversified Fund      
Variable Interest Entity [Line Items]      
Payments of capital distributions 255,500 333,400  
Not Primary Beneficiary | Investor | RenaissanceRe Upsilon Diversified Fund | Preference shares      
Variable Interest Entity [Line Items]      
Investment in variable interest entity 17,500 16,900  
Not Primary Beneficiary | Investor | NOC1 | Preference shares      
Variable Interest Entity [Line Items]      
Investment in variable interest entity   20,000  
Redemption of preference shares   48,800  
Not Primary Beneficiary | Investor | Stratos | Preference shares      
Variable Interest Entity [Line Items]      
Investment in variable interest entity 260,400    
Not Primary Beneficiary | Renaissance Reinsurance | Mona Lisa Re      
Variable Interest Entity [Line Items]      
Ceded premiums written 56,500 45,200 32,800
Ceded premiums earned 63,900 39,500 32,800
Not Primary Beneficiary | DaVinci Reinsurance | Mona Lisa Re      
Variable Interest Entity [Line Items]      
Ceded premiums written 14,100 11,700 8,200
Ceded premiums earned $ 16,000 $ 10,300 $ 8,200