v3.25.4
Financial Risk Management (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Financial Risk Management    
Cumulative translation adjustment $ 91.2 $ (131.3)
Investments $ 1,141.3 325.5
Commodity Price Risk    
Financial Risk Management    
Impact to revenue 10.00%  
10% increase $ 127.6 70.7
10% decrease $ (127.6) $ (70.7)
Increase in equity price risk rate used for sensitivity analysis (as a percent) 10.00% 10.00%
Decrease in equity price risk rate used for sensitivity analysis (as a percent) 10.00%  
Foreign Exchange Risk    
Financial Risk Management    
Cumulative translation adjustment $ 91.2 $ (131.3)
Interest Rate Risk    
Financial Risk Management    
Interest rate sensitivities increase effect on net income 2.6 6.2
Interest rate sensitivities decrease effect on net income (2.2) (5.5)
Interest rate sensitivities increase effect on equity 2.6 6.2
Interest rate sensitivities decrease effect on equity $ (2.2) $ (5.5)
Increase in interest rate used for sensitivity analysis (as a percent) 0.50% 0.50%
Decrease in interest rate used for sensitivity analysis (as a percent) 0.50% 0.50%
Other Price Risk    
Financial Risk Management    
Increase in equity price risk rate used for sensitivity analysis (as a percent) 10.00% 10.00%
Decrease in equity price risk rate used for sensitivity analysis (as a percent) 10.00% 10.00%
Equity price sensitivity increase effect on net income $ 4.5 $ 0.2
Equity price sensitivity decrease effect on net income (4.4) (0.2)
Equity price sensitivity increase effect on other comprehensive income or loss 95.9 28.2
Equity price sensitivity decrease effect on other comprehensive income or (loss) (95.9) (28.2)
Liquidity Risk    
Financial Risk Management    
Cash and cash equivalents and available-for-sale securities $ 670.9 1,451.3
Term of financial liabilities 1 year  
Capital Risk Management    
Financial Risk Management    
Cash and cash equivalents and available-for-sale securities $ 670.9 1,451.3
Investments 1,141.3 325.5
Liquid securities 1,093.3 316.8
Capital Risk Management | Labrador Iron Ore Royalty Corporation    
Financial Risk Management    
Liquid securities 138.0 127.3
Capital Risk Management | Credit Facility    
Financial Risk Management    
Undrawn borrowing facilities $ 1,000.0 $ 1,000.0