v3.26.1
Financial instruments - Carrying amounts and fair values (Detail)
$ in Millions
 6 Months Ended
Mar. 12, 2025
USD ($)
tranche
Jun. 30, 2026
USD ($)
lender
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Mar. 14, 2025
USD ($)
Disclosure of detailed information about borrowings [line items]          
Borrowings (including overdrafts), carrying value   $ 21,414   $ 21,931  
Borrowings (including overdrafts), fair value   21,245   21,933  
Proceeds from additional borrowings, net of issue costs [1]   431 $ 15,952    
Listed bonds          
Disclosure of detailed information about borrowings [line items]          
Borrowings (including overdrafts), carrying value   17,141   17,336  
Borrowings (including overdrafts), fair value   16,851   17,148  
Oyu Tolgoi project finance          
Disclosure of detailed information about borrowings [line items]          
Borrowings (including overdrafts), carrying value   3,277   3,755  
Borrowings (including overdrafts), fair value   3,439   3,990  
Rincon project finance          
Disclosure of detailed information about borrowings [line items]          
Borrowings (including overdrafts), carrying value   158   0  
Borrowings (including overdrafts), fair value   158   0  
Notional amount   $ 1,175      
Debt instrument period (in years) 10 years        
Number of international lenders | lender   4      
Proceeds from additional borrowings, net of issue costs   $ 175      
Other          
Disclosure of detailed information about borrowings [line items]          
Borrowings (including overdrafts), carrying value   838   840  
Borrowings (including overdrafts), fair value   $ 797   $ 795  
Fixed And Floating Rate SEC-Registered Debt Securities          
Disclosure of detailed information about borrowings [line items]          
Notional amount $ 9,000       $ 9,000
Number of tranches | tranche 8        
Three Year Note, Floating Rate          
Disclosure of detailed information about borrowings [line items]          
Notional amount $ 500        
Debt instrument period (in years) 3 years        
Three Year Note, Floating Rate | Floating interest rate          
Disclosure of detailed information about borrowings [line items]          
Basis spread on variable rate 0.84%        
Fixed Coupon Rate | Minimum | Fixed interest rate          
Disclosure of detailed information about borrowings [line items]          
Basis spread on variable rate 4.375%        
Fixed Coupon Rate | Maximum | Fixed interest rate          
Disclosure of detailed information about borrowings [line items]          
Basis spread on variable rate 5.875%        
[1]
In 2026, we drew down US$175 million of the US$1,175 million Rincon funding facility, with proceeds recorded net of transaction costs. In
2025, we drew down on our US$7 billion bridge loan facility to fund the acquisition of Arcadium Lithium plc. The facility was subsequently
repaid on 19 March 2025 following our US$9 billion bond issuance of fixed and floating rate SEC-registered debt securities on 14 March
2025. Refer to note 10 for further details.