v3.26.1
Contingencies (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Applicability, Impact and Conclusion of Environmental Loss Contingencies [Abstract]    
Environmental contingency accrual $ 171.8 $ 192.2
Loss Contingencies [Line Items]    
Accrued Environmental Loss Contingencies, Noncurrent $ 82.8 104.3
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Accrued liabilities  
Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration] Accrued liabilities  
Environmental Loss Contingency, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other noncurrent liabilities  
Accrued Environmental Loss Contingencies, Current $ 89.0 $ 87.9
New Wales Phase II West Stack    
Loss Contingencies [Line Items]    
Maximum potential liabilitiy 55.5  
Brazilian subsidiary judicial and administrative proceedings    
Loss Contingencies [Line Items]    
Maximum potential liabilitiy 73.3  
Brazilian subsidiary labor claims    
Loss Contingencies [Line Items]    
Loss Contingency Accrual 52.8  
Maximum | Brazilian subsidiary judicial and administrative proceedings    
Loss Contingencies [Line Items]    
Maximum potential liabilitiy 541.6  
Maximum | Brazilian Non Income Tax Proceedings    
Loss Contingencies [Line Items]    
Maximum potential liabilitiy 782.8  
Maximum | Brazilian Non Income Tax Proceedings | Indemnification Agreement Vale S.A.    
Loss Contingencies [Line Items]    
Maximum potential liabilitiy 200.6  
Maximum | Brazilian Non Income Tax Proceedings | PIS And Cofins Cases    
Loss Contingencies [Line Items]    
Maximum potential liabilitiy 470.6  
Maximum | Brazilian subsidiary labor claims    
Loss Contingencies [Line Items]    
Maximum potential liabilitiy $ 392.1