v3.24.2.u1
Climate change - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended 120 Months Ended
Jun. 30, 2024
Jun. 30, 2030
Jun. 30, 2023
Jun. 30, 2022
Disclosure Of Climate Change [Line Items]        
Assets (liabilities) $ (49,120)   $ (48,530)  
Property, plant and equipment 71,629   71,818 $ 61,295
Amount By which metallurgical coal assets carrying value of asset exceedsIts estimated valuation 6,000      
Surrender of carbon credits 1      
Carbon credits attributable to intangible assets 23      
Carbon credits surrender obligation 17      
Lease liabilities 3,116   3,019  
Fair value of financial derivatives 1,610   1,585  
Expenditure to support value chain 30      
Increase decrease in rehabilitation provision due to change in the life of mines 40      
Power purchase contract agreements [member]        
Disclosure Of Climate Change [Line Items]        
Lease liabilities 44    
Fair value of financial derivatives 92   $ 50  
Operating segments [member] | Coal [member] | New South Wales Energy Coal [member]        
Disclosure Of Climate Change [Line Items]        
Assets (liabilities) 200      
Property, plant and equipment 540      
Provisions and other liabilities 740      
Provisions ​for equitable transition $ 0      
Scenario Forecast [member]        
Disclosure Of Climate Change [Line Items]        
Decrease In Percentage Of Reduction Of Operational GHG Emissions   30.00%    
Bottom of range [member] | Operating segments [member]        
Disclosure Of Climate Change [Line Items]        
Discount rate used in current estimate of value in use 7.00%   7.00%  
Top of range [member] | Operating segments [member]        
Disclosure Of Climate Change [Line Items]        
Discount rate used in current estimate of value in use 9.50%   9.50%  
Maximum [Member]        
Disclosure Of Climate Change [Line Items]        
Commitments for capital expenditure $ 4,000