v3.26.1
Financial Instruments and Risk Management (Contractual Commitments) (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about financial instruments [abstract]      
Operating and financing leases, less than 1 year $ 14.4    
Operating and financing leases, 2-3 years 15.0    
Operating and financing leases, 4-5 years 3.8    
Operating and financing leases, more than 5 years 8.6    
Operating and financing leases, total 41.8    
Debt, less than 1 year 0.0    
Debt, 2-3 years 200.0    
Debt, 4-5 years 0.0    
Debt, more than 5 years 0.0    
Debt total 200.0 $ 250.0 $ 0.0
Accounts payable and accrued liabilities, less than 1 year 316.1 233.0  
Accounts payable and accrued liabilities, 2-3 years 0.0    
Accounts payable and accrued liabilities, 4-5 years 0.0    
Accounts payable and accrued liabilities, more than 5 years 0.0    
Accounts payable and accrued liabilities, total 316.1    
Decommissioning liability, less than 1 year 8.1    
Decommissioning liability, 2-3 years 48.5    
Decommissioning liability, 4-5 years 44.4    
Decommissioning liability, more than 5 years 106.5    
Decommissioning liability, total 207.5 $ 193.8  
Capital commitments, less than 1 year 233.3    
Capital commitments, 2-3 years 13.8    
Capital commitments, 4-5 years 3.4    
Capital commitments, more than 5 years 10.3    
Capital commitments, total 260.8    
Contractual obligation, less than 1 year 571.9    
Contractual obligation, 2-3 years 77.3    
Contractual obligation, 4-5 years 251.6    
Contractual obligation, more than 5 years 125.4    
Contractual obligation, total $ 1,026.2