v3.26.1
Financial Instruments and Other Guarantees (Details)
$ in Millions, $ in Millions
Mar. 31, 2026
USD ($)
Mar. 31, 2026
AUD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2025
AUD ($)
Guarantee Obligations [Line Items]        
Restricted Cash $ 675.9   $ 709.2  
Restricted cash and collateral 811.3   844.1  
Surety Trust Account        
Guarantee Obligations [Line Items]        
Restricted Cash 377.7   383.6  
Deposits with Regulatory Authorities        
Guarantee Obligations [Line Items]        
Deposits Assets 135.4 $ 198.0 134.9 $ 201.0
Cash backed bank guarantees        
Guarantee Obligations [Line Items]        
Restricted Cash   $ 319.0   $ 312.0
Collateralized letters of credit funding        
Guarantee Obligations [Line Items]        
Restricted Cash 298.2   $ 325.6  
Asset Retirement Obligations        
Guarantee Obligations [Line Items]        
Surety bonds amount 937.5      
Letters of credit outstanding, amount 53.5      
Surety Bonds and Letters of Credit Outstanding for Reclamation Support 991.0      
Less: Letters of Credit in Support of Surety Bonds 53.5      
Total Obligations Supported, Net 937.5      
Asset Retirement and Other Obligations        
Guarantee Obligations [Line Items]        
Surety bonds amount 1,019.6      
Letters of credit outstanding, amount 115.2      
Total Surety Bonds and Letters of Credit Outstanding 1,134.8      
Total Letters of Credit in Support of Surety Bonds (55.2)      
Total Obligations Supported, Net 1,079.6      
Other Obligations        
Guarantee Obligations [Line Items]        
Surety bonds amount 82.1      
Letters of credit outstanding, amount 61.7      
Surety Bonds and Letters of Credit Outstanding for Other Support 143.8      
Less: Letters of Credit in Support of Surety Bonds 1.7      
Total Obligations Supported, Net 142.1      
Secured debt | Accounts Receivable Securitization Program        
Guarantee Obligations [Line Items]        
Letters of credit outstanding, amount 66.0      
Letter of Credit        
Guarantee Obligations [Line Items]        
Letters of credit outstanding, amount 49.2      
Collateralized Letter of Credit Agreement        
Guarantee Obligations [Line Items]        
Letters of credit outstanding, amount $ 78.1