v3.25.4
Financial Risk Management - Capital Management - Additional disclosures (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2025
USD ($)
shares
Dec. 31, 2024
USD ($)
shares
Financial Risk Management.    
Net earnings attributable to shareholders of Fairfax $ 4,772.4 $ 3,874.9
Cash consideration for cancellation of shares 1,625.2 $ 1,588.4
Payments of common and preferred share dividends $ 368.1  
Percentage of consolidated net debt/net total capital ratio 26.10% 24.60%
Percentage of consolidated total debt/total capital ratio 30.60% 29.30%
National Association of Insurance Commissioners    
Financial Risk Management.    
Capital and surplus, regulatory minimum requirement multiplier 2 2
Bermuda Monetary Authority    
Financial Risk Management.    
Target capital level percentage 120.00%  
Office of the Superintendent of Financial Institutions    
Financial Risk Management.    
Minimum supervisory target 150.00%  
Odyssey Group, Crum & Forster, Zenith National, Allied World and U.S. Run-off excluding TIG Insurance | National Association of Insurance Commissioners | Minimum    
Financial Risk Management.    
Capital and surplus, actual multiplier 3.3 3.3
TIG Insurance | National Association of Insurance Commissioners | Minimum    
Financial Risk Management.    
Capital and surplus, actual multiplier 2 2.1
Northbridge | Office of the Superintendent of Financial Institutions    
Financial Risk Management.    
Weighted average MCT ratio 249.00% 227.00%
Brit    
Financial Risk Management.    
Subordinated debt and contingent funding in the form of letters of credit $ 3,551.3 $ 2,541.7
Surplus over the management capital requirements 1,524.7 823.1
KI    
Financial Risk Management.    
Subordinated debt and contingent funding in the form of letters of credit 802.1 728.4
Surplus over the management capital requirements $ 126.3 $ 203.6
Gulf Insurance    
Financial Risk Management.    
Regulatory solvency capital 1516.10% 960.20%
Common shares    
Financial Risk Management.    
Equity in stock $ 26,282.6 $ 22,959.8
Subordinate voting shares    
Financial Risk Management.    
Purchases for cancellation (in shares) | shares 1,006,535 1,346,953
Other comprehensive income, cumulative movement $ 424.6  
Subordinate voting shares | Common shareholders' equity    
Financial Risk Management.    
Cash consideration for cancellation of shares $ 1,625.2