v3.26.3
Financial Instruments and Other Guarantees (Details)
$ in Millions, $ in Millions
Sep. 30, 2026
USD ($)
Sep. 30, 2026
AUD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2025
AUD ($)
Guarantee Obligations [Line Items]        
Restricted Cash $ 361.2   $ 709.2  
Restricted cash and collateral 418.4   844.1  
Surety Trust Account        
Guarantee Obligations [Line Items]        
Restricted Cash 311.1   383.6  
Deposits with Regulatory Authorities        
Guarantee Obligations [Line Items]        
Deposits Assets 57.2 $ 82.0 134.9 $ 201.0
Cash backed bank guarantees        
Guarantee Obligations [Line Items]        
Restricted Cash   $ 22.0   $ 312.0
Collateralized letters of credit funding        
Guarantee Obligations [Line Items]        
Restricted Cash 50.1   $ 325.6  
Asset Retirement Obligations        
Guarantee Obligations [Line Items]        
Surety bonds amount 1,205.4      
Letters of credit outstanding, amount 62.3      
Surety Bonds and Letters of Credit Outstanding for Reclamation Support 1,267.7      
Less: Letters of Credit in Support of Surety Bonds 62.3      
Total Obligations Supported, Net 1,205.4      
Asset Retirement and Other Obligations        
Guarantee Obligations [Line Items]        
Surety bonds amount 1,287.1      
Letters of credit outstanding, amount 115.7      
Total Surety Bonds and Letters of Credit Outstanding 1,402.8      
Total Letters of Credit in Support of Surety Bonds (64.2)      
Total Obligations Supported, Net 1,338.6      
Other Obligations        
Guarantee Obligations [Line Items]        
Surety bonds amount 81.7      
Letters of credit outstanding, amount 53.4      
Surety Bonds and Letters of Credit Outstanding for Other Support 135.1      
Less: Letters of Credit in Support of Surety Bonds 1.9      
Total Obligations Supported, Net 133.2      
Accounts Receivable Securitization Program        
Guarantee Obligations [Line Items]        
Letters of credit outstanding, amount 57.5      
Letter of Credit        
Guarantee Obligations [Line Items]        
Letters of credit outstanding, amount 58.2      
Collateralized Letter of Credit Agreement        
Guarantee Obligations [Line Items]        
Letters of credit outstanding, amount $ 34.0