v3.26.3
Investments - Investment in Fortitude (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]          
Investment $ 3,069.4   $ 3,069.4   $ 2,879.5
Performance revenues (507.3) $ (519.0) (1,010.1) $ 334.8  
Principal investment income (loss)          
Schedule of Equity Method Investments [Line Items]          
Performance revenues 119.3 87.7 252.9 79.8  
Carlyle FRL          
Schedule of Equity Method Investments [Line Items]          
Investment 743.0   743.0    
Investment, cost 666.8   $ 666.8    
Carlyle FRL | Fortitude Group Holdings, LLC          
Schedule of Equity Method Investments [Line Items]          
Ownership percentage     10.50%    
Fortitude Group Holdings, LLC | Fortitude Re          
Schedule of Equity Method Investments [Line Items]          
Committed capital 27,400.0   $ 27,400.0    
Fortitude Group Holdings, LLC | Carlyle FRL          
Schedule of Equity Method Investments [Line Items]          
Ownership percentage acquired     38.50%    
Dividends     $ 300.0 300.0  
Fortitude Group Holdings, LLC | Carlyle FRL | Principal investment income (loss)          
Schedule of Equity Method Investments [Line Items]          
Performance revenues $ 31.3 $ 31.4 $ 31.3 $ 31.4  
Fortitude Group Holdings, LLC | Carlyle FRL, L.P. and Other Third-Party Investors          
Schedule of Equity Method Investments [Line Items]          
Ownership percentage acquired     97.50%