v3.25.4
Financial Risk Management - Market Risk - Foreign currency effects on the consolidated statement of other comprehensive income (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Feb. 20, 2025
Bangalore Airport | Non-insurance associates and joint ventures | Fairfax India      
Financial Risk Management      
Percentage of interests acquired     10.00%
Canada, Dollars      
Financial Risk Management      
Assets $ 13,145.2 $ 12,226.6  
Liabilities (7,922.8) (7,164.8)  
Net asset exposure before hedge of net investment 5,222.4 5,061.8  
Hedge of net investment (2,797.4) (2,175.7)  
Net asset exposure after hedge of net investment 2,425.0 2,886.1  
Hypothetical change in pre-tax other comprehensive income (loss) (242.5) (288.6)  
Hypothetical change in other comprehensive income (loss) (232.4) (284.9)  
Euro Member Countries, Euro      
Financial Risk Management      
Assets 10,752.4 9,488.8  
Liabilities (7,369.6) (6,800.3)  
Net asset exposure before hedge of net investment 3,382.8 2,688.5  
Hedge of net investment (877.0) (771.7)  
Net asset exposure after hedge of net investment 2,505.8 1,916.8  
Hypothetical change in pre-tax other comprehensive income (loss) (250.6) (191.7)  
Hypothetical change in other comprehensive income (loss) (183.4) (147.4)  
United Kingdom, Pounds      
Financial Risk Management      
Assets 3,014.3 2,699.4  
Liabilities (2,042.9) (1,854.6)  
Net asset exposure before hedge of net investment 971.4 844.8  
Net asset exposure after hedge of net investment 971.4 844.8  
Hypothetical change in pre-tax other comprehensive income (loss) (97.2) (84.5)  
Hypothetical change in other comprehensive income (loss) (94.8) (83.1)  
India, Rupees      
Financial Risk Management      
Assets 4,389.4 4,183.8  
Liabilities (1,461.9) (1,366.2)  
Net asset exposure before hedge of net investment 2,927.5 2,817.6  
Net asset exposure after hedge of net investment 2,927.5 2,817.6  
Hypothetical change in pre-tax other comprehensive income (loss) (292.8) (281.8)  
Hypothetical change in other comprehensive income (loss) $ (277.1) $ (263.2)