v3.25.4
Statutory Requirements (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Statutory Requirements    
Common share dividends $ 525.4 $ 657.8
Dividend capacity available 4,065.9  
North American Insurers    
Statutory Requirements    
Dividend capacity available 936.0  
North American Insurers | Northbridge    
Statutory Requirements    
Dividend capacity available 550.9  
North American Insurers | Crum & Forster    
Statutory Requirements    
Dividend capacity available 315.2  
North American Insurers | Zenith National    
Statutory Requirements    
Dividend capacity available 69.9  
Global Insurers and Reinsurers    
Statutory Requirements    
Dividend capacity available 2,954.6  
Global Insurers and Reinsurers | Allied World    
Statutory Requirements    
Dividend capacity available 1,684.3  
Global Insurers and Reinsurers | Odyssey Group    
Statutory Requirements    
Dividend capacity available 953.0  
Global Insurers and Reinsurers | Brit    
Statutory Requirements    
Dividend capacity available 258.6  
Global Insurers and Reinsurers | Ki    
Statutory Requirements    
Dividend capacity available 58.7  
International Insurers and Reinsurers | Gulf Insurance    
Statutory Requirements    
Dividend capacity available 175.3  
Insurance and reinsurance companies    
Statutory Requirements    
Common share dividends $ 1,678.1 $ 1,955.6