v3.26.1
Fair Value Measurements - Schedule of Fair Value Measurements of Asset and Liability Instruments (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Assets:    
Derivative assets $ 22 $ 5
Liabilities:    
Derivative liabilities   44
Financing arrangements - precious metals    
Assets:    
Derivative assets   0
Liabilities:    
Derivative liabilities   33
Foreign currency forward contracts    
Assets:    
Derivative assets   0
Liabilities:    
Derivative liabilities   6
Level 1    
Assets:    
Total assets 3 0
Liabilities:    
Environmental credit obligations 0 0
Total liabilities 0 0
Level 1 | Commodity contracts    
Assets:    
Derivative assets 3 0
Liabilities:    
Derivative liabilities 0 0
Level 1 | Financing arrangements - precious metals    
Liabilities:    
Derivative liabilities 0 0
Level 1 | Foreign currency forward contracts    
Assets:    
Derivative assets 0  
Liabilities:    
Derivative liabilities   0
Level 2    
Assets:    
Total assets 18 5
Liabilities:    
Environmental credit obligations 498 46
Total liabilities 602 153
Level 2 | Commodity contracts    
Assets:    
Derivative assets 4 5
Liabilities:    
Derivative liabilities 5 5
Level 2 | Financing arrangements - precious metals    
Liabilities:    
Derivative liabilities 99 96
Level 2 | Foreign currency forward contracts    
Assets:    
Derivative assets 14  
Liabilities:    
Derivative liabilities   6
Level 3    
Assets:    
Total assets 1 0
Liabilities:    
Environmental credit obligations 0 0
Total liabilities 0 0
Level 3 | Commodity contracts    
Assets:    
Derivative assets 1 0
Liabilities:    
Derivative liabilities 0 0
Level 3 | Financing arrangements - precious metals    
Liabilities:    
Derivative liabilities 0 0
Level 3 | Foreign currency forward contracts    
Assets:    
Derivative assets 0  
Liabilities:    
Derivative liabilities   0
Carrying Amount    
Assets:    
Total assets 22 5
Liabilities:    
Environmental credit obligations 498 46
Total liabilities 598 151
Carrying Amount | Commodity contracts    
Assets:    
Derivative assets 8 5
Liabilities:    
Derivative liabilities 5 5
Carrying Amount | Financing arrangements - precious metals    
Liabilities:    
Derivative liabilities 95 94
Carrying Amount | Foreign currency forward contracts    
Assets:    
Derivative assets $ 14  
Liabilities:    
Derivative liabilities   $ 6