v3.25.0.1
Financial Instruments and Risk Management (Contractual Commitments) (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about financial instruments [abstract]    
Operating and financing leases, less than 1 year $ 17.2  
Operating and financing leases, 2-3 years 19.7  
Operating and financing leases, 4-5 years 2.7  
Operating and financing leases, more than 5 years 0.0  
Operating and financing leases, total 39.6  
Debt, less than 1 year 0.0  
Debt, 2-3 years 250.0  
Debt, 4-5 years 0.0  
Debt, more than 5 years 0.0  
Debt total 250.0 $ 0.0
Accounts payable and accrued liabilities, less than 1 year 233.0 194.0
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 233.0  
Decommissioning liability, less than 1 year 6.5  
Decommissioning liability, 2-3 years 36.6  
Decommissioning liability, 4-5 years 58.7  
Decommissioning liability, more than 5 years 92.0  
Decommissioning liability, total 193.8 $ 165.2
Capital commitments, less than 1 year 131.1  
Capital commitments, 2-3 years 6.0  
Capital commitments, 4-5 years 0.0  
Capital commitments, more than 5 years 0.0  
Capital commitments, total 137.1  
Contractual obligation, less than 1 year 387.8  
Contractual obligation, 2-3 years 62.3  
Contractual obligation, 4-5 years 311.4  
Contractual obligation, more than 5 years 92.0  
Contractual obligation, total $ 853.5