XML 39 R31.htm IDEA: XBRL DOCUMENT v3.19.2
Impairment charges - Narrative (Details) - USD ($)
$ in Millions
 6 Months Ended
Jul. 16, 2019
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Disclosure of impairment loss and reversal of impairment loss [line items]        
Impairment loss   $ 859 $ 98  
Property development and project management expense $ 5,300      
Aluchemie Anode Plant        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Interest Sold (as a percent)     53.30%  
Sales Price Agreed For Disposal Of Subsidiary     $ 345  
Impairment loss     $ (123)  
Aluminium Fluoride Plant        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Interest Sold (as a percent)     50.00%  
Discount rate applied (as a percent)   6.90%    
ISAL Smelter, Aluchemie Anode Plant and Aluminium Fluoride Plant        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Recoverable amount   $ 302    
Alufluor        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Recoverable amount   $ 46    
Oyo Tolgoi Copper-Gold Mine        
Disclosure of impairment loss and reversal of impairment loss [line items]        
NCI share of Impairment   66.00%    
Rio share of impairment   34.00%    
Rio Share Of Impairment, Value   $ 800    
Tax Impact of impairment   320    
Tax Losses Expected To Expire   $ 359    
Discount rate applied (as a percent)   8.30%   8.00%
Recoverable amount   $ 8,300    
Discount rate assumption (as a percent)   1.00%    
Recoverable amount assumption   $ 1,500    
10% decease in recoverability   2,200    
10% Increase in recoverability   2,100    
Aluminium        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Impairment loss   86 $ 98  
Pre-tax        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Impairment loss   2,349    
Pre-tax | Oyo Tolgoi Copper-Gold Mine        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Impairment loss   (2,200)    
Pre-tax | Aluminium        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Impairment loss   109    
Post Tax        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Impairment loss   16    
Post Tax | Oyo Tolgoi Copper-Gold Mine        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Impairment loss   (2,300)    
Post Tax | Aluminium        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Impairment loss   $ (23)    
Minimum        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Increase in project expenses 1,200      
Maximum        
Disclosure of impairment loss and reversal of impairment loss [line items]        
Increase in project expenses $ 1,900