XML 593 R113.htm IDEA: XBRL DOCUMENT v3.20.4
Impairment charges - Additional information (Detail) - USD ($)
$ in Millions
 6 Months Ended 9 Months Ended 12 Months Ended
Dec. 16, 2020
Jul. 09, 2020
Jul. 16, 2019
Jun. 30, 2020
Jun. 30, 2019
Sep. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Impairment loss recognised in profit or loss             $ 904 $ 3,487 $ 132
Cash flows from consolidated operations [1]             21,822 19,705 15,655
Pacific Aluminium                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Contract termination notice period   14 months              
Pacific Aluminium | Aluminium                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Recoverable amount of asset or cash-generating unit             $ 273    
Discount rate applied to cash flow projections             6.60%    
Pre-tax impairment charge net of reversals             $ (26)    
Pacific Aluminium | Aluminium | Pre Tax                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Pre-tax impairment charge net of reversals             (36)    
Pacific Aluminum Smelter | Aluminium                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Pre-tax impairment charge net of reversals             (119)    
Pacific Aluminum Smelter | Aluminium | Pre Tax                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Pre-tax impairment charge net of reversals             (148)    
Sohar | Aluminium                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Recoverable amount of asset or cash-generating unit           $ 258      
Discount rate applied to cash flow projections           7.60%      
Sohar | Aluminium | Investment in equity accounted units ("EAUs")                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Impairment loss recognised in profit or loss           $ 220      
ISAL | Aluminium                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Recoverable amount of asset or cash-generating unit             $ 139 $ 302  
Discount rate applied to cash flow projections             6.60% 6.90%  
Pre-tax impairment charge net of reversals       $ (204)       $ (109) 123
Reversal of impairment loss recognised in profit or loss             $ 111    
ISAL | Alufluor Ab | Aluminium                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Recoverable amount of asset or cash-generating unit               46  
ISAL | Assets and liabilities classified as held for sale                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Business acquisition binding offer amount                 $ 345
ISAL | Assets and liabilities classified as held for sale | Aluminerie Alouette Inc. | Netherlands                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Percentage of ownership interest to be sold                 53.30%
ISAL | Assets and liabilities classified as held for sale | Alufluor Ab | Sweden                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Percentage of ownership interest to be sold                 50.00%
Diavik | Copper & Diamonds                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Proportion of ownership interest in joint venture             40.00%    
Oyu Tolgoi | Copper & Diamonds                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Recoverable amount of asset or cash-generating unit         $ 8,300        
Discount rate applied to cash flow projections       8.30%          
Property development and project management expense $ 6,750   $ 5,300            
Recoverable amount of asset or cash generating unit, percent       20.00%          
Deferred tax expense (income) relating to origination and reversal of temporary differences         320        
Deductible temporary differences for which no deferred tax asset is recognised         359        
Carrying amount of asset or cash-generating unit             $ 10,100    
Cash flows from consolidated operations             $ 1,100    
Oyu Tolgoi | Copper & Diamonds | Pre Tax                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Pre-tax impairment charge net of reversals         $ (2,200)        
Yarwun Alumina Refinery | Aluminium                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Impairment loss recognised in profit or loss               $ 1,138  
Impairment loss, annual reduction, percent               30.00%  
Bottom of range | Oyu Tolgoi | Copper & Diamonds                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Production delay period     16 months            
Property development and project management expense, estimated increase     $ 1,200            
Top of range | Oyu Tolgoi | Copper & Diamonds                  
Disclosure of impairment loss and reversal of impairment loss [line items]                  
Production delay period     30 months            
Property development and project management expense, estimated increase     $ 1,900            
[1]
(a) Cash flows from consolidated operations
Profit after tax for the year10,400 6,972 13,925 
Adjustments for:
– Taxation4,991 4,147 4,242 
– Finance items1,751 648 33 
– Share of profit after tax of equity accounted units(652)(301)(513)
– Net losses/(gains) on consolidation and disposal of interests in businesses36— 291 (4,622)
– Impairment charges of investments in equity accounted units after tax6339 — — 
– Impairment charges6904 3,487 132 
– Depreciation and amortisation4,279 4,384 4,015 
– Provisions (including exchange differences on provisions)894 753 1,011 
Utilisation of provisions(582)(539)(620)
Utilisation of provision for post-retirement benefits25(192)(205)(219)
Change in inventories(281)28 (587)
Change in receivables and other assets(562)163 (421)
Change in trade and other payables558 (191)476 
Other items(d)
(25)68 (1,197)
21,822 19,705 15,655