v3.25.2
Closure and Rehabilitation Provisions - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2023
Disclosure of other provisions [line items]      
Proportion of the entity undiscounted forecast cashflows 100.00% 100.00%  
Closure and rehabilitation provisions [member]      
Disclosure of other provisions [line items]      
Reasonably possible acceleration in forecast cash flows 1 year    
Percentage of reasonably possible increase in real discount rates 0.50%    
Decrease in closure and rehabilitation provision due to reasonably possible increase in real discount rates $ 665    
Decrease in depreciation expense due to reasonably possible increase in real discount rates 27    
Increase in net finance costs due to reasonably possible increase in real discount rates 29    
Increase in Provision due to reasonably possible acceleration in forecast cash flows 291    
Increase decrease in provision due to changes in discount rate $ 340    
Closure and rehabilitation provisions [member] | After Thirty Years [Member]      
Disclosure of other provisions [line items]      
Proportion of the entity undiscounted forecast cashflows 44.00% 52.00%  
Closure and rehabilitation provisions [member] | Bottom of range [member]      
Disclosure of other provisions [line items]      
Remaining production life 4 years 5 years  
Closure and rehabilitation provisions [member] | Top of range [member]      
Disclosure of other provisions [line items]      
Remaining production life 86 years 87 years  
Closure and rehabilitation provisions [member] | Closed and contaminated sites rehabilitation asset [member]      
Disclosure of other provisions [line items]      
Increases to existing and new provisions associated closure and remediation costs charged to the income statement $ 101 $ 38 $ 4
Decrease in income statement charge due to reasonably possible increase in real discount rates 222    
Increase decrease ​in income statement charge due​ to reasonable possible acceleration​ in forecast ​of cash​ flows 122    
Increase decrease in provision due to changes in discount rate 110    
Closure and rehabilitation provisions [member] | Operating sites [member]      
Disclosure of other provisions [line items]      
Decrease in property, plant and equipment due to reasonably possible increase in real discount rates 443    
Increase in property, plant and equipment due to reasonably possible acceleration in forecast cash flows $ 169