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Impairment charges - Additional information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge $ 134,000,000    
Deferred tax assets 3,137,000,000 $ 3,395,000,000  
Pre-tax impairment charge net of reversals $ 132,000,000 796,000,000 $ 249,000,000
Increase in discount rate 1.90%    
Reduction of the copper price throughout the life of mine $ 0.39    
long term reduction in copper price 13.00%    
Property, plant and equipment [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge net of reversals $ 130,000,000 435,000,000 248,000,000
Australia [Member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Deferred tax assets 796,000,000 1,055,000,000  
Canada [Member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Deferred tax assets 545,000,000 546,000,000  
Mongolia [Member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Deferred tax assets 703,000,000 631,000,000  
Mongolia [Member] | Copper & Diamonds [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Recoverable amount of asset or cash-generating unit 1,100,000,000 1,300,000,000  
Pre-tax impairment charge net of reversals $ 0    
Net present value of post tax cash flows discounted percentage 8.00%    
Carrying value from cash generating unit $ 3,100,000,000    
Assets and liabilities classified as held for sale [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Deferred tax assets 66,000,000 49,000,000  
ISAL Smelter [member] | Assets and liabilities classified as held for sale [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Business acquisition binding offer amount $ 345,000,000    
ISAL Smelter [member] | Assets and liabilities classified as held for sale [member] | Aluminerie Alouette Inc | Netherlands [Member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Percentage of ownership interest to be sold 53.30%    
ISAL Smelter [member] | Assets and liabilities classified as held for sale [member] | Alufluor Ab | Sweden [Member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Percentage of ownership interest to be sold 50.00%    
Rossing [member] | Energy & Minerals [Member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge net of reversals $ 9,000,000 267,000,000  
Rossing [member] | Namibia [Member] | Energy & Minerals [Member] | Property, plant and equipment [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge   267,000,000  
Rossing [member] | Namibia, Dollars | Energy & Minerals [Member] | Property, plant and equipment [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge $ 9,000,000    
Argyle Diamond Mine [member] | Copper & Diamonds [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge net of reversals   172,000,000 241,000,000
Argyle Diamond Mine [member] | Australia [Member] | Copper & Diamonds [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge   172,000,000  
Description of impairment trigger assessment In 2016, our annual impairment trigger assessment at the Argyle CGU identified the impact of lower production volumes compared with forecast and lower prices achieved for bulk diamonds as impairment indicators. We calculated a recoverable amount for Argyle of US$191 million, resulting in a pre-tax impairment charge of US$241 million to property, plant and equipment and intangible assets. In 2017, our annual impairment trigger assessment at the Argyle CGU identified impairment indicators because of lower production volumes compared with forecast, a smaller than expected contribution from productivity improvements and lower realised prices. In assessing the recoverable amount of the assets, we determined that the property, plant and equipment, including an updated closure asset, was fully impaired resulting in a pre-tax impairment charge of US$172 million. The impairment charge resulted in the recognition of deferred tax assets of US$34 million, which will be recovered by other business units in the same tax group.    
Deferred tax assets   34,000,000  
Recoverable amount of asset or cash-generating unit     191,000,000
Argyle Diamond Mine [member] | Australia [Member] | Copper & Diamonds [member] | Property, plant and equipment [member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge     $ 241,000,000
Roughrider [member] | Energy & Minerals [Member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge net of reversals   357,000,000  
Roughrider [member] | Canada [Member] | Energy & Minerals [Member]      
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Line Items]      
Pre-tax impairment charge net of reversals   $ 357,000,000