v3.26.3
General Information - Additional Information (Details) - USD ($)
shares in Millions, $ in Millions
 1 Months Ended 9 Months Ended
May 31, 2026
Sep. 30, 2024
Sep. 30, 2026
Sep. 30, 2025
May 01, 2026
Apr. 30, 2026
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]            
Acquisition of additional ownership interest in Cerro Verde     $ (109)      
Deferred income taxes     149 $ (16)    
Capital in Excess of Par Value            
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]            
Acquisition of additional ownership interest in Cerro Verde     $ (73)      
Noncontrolling Interests            
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]            
Acquisition of additional ownership interest in Cerro Verde   $ (36)        
Cerro Verde            
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]            
Shares purchased (in shares) 2.0          
Value of shares purchased $ 107          
Investment owned, percent         55.66% 55.08%
Deferred income taxes 2          
Cerro Verde | Capital in Excess of Par Value            
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]            
Acquisition of additional ownership interest in Cerro Verde (73)          
Cerro Verde | Noncontrolling Interests            
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]            
Acquisition of additional ownership interest in Cerro Verde $ (36)