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Provisions, contingent liabilities and other liabilities - Additional information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Provisions and contingent liabilities          
Current provisions $ 72,771 $ 68,172      
Provision for closure of mining units and exploration projects at future value 296,200 $ 280,300      
Period Used To Reflect Time Value Of Money For Provisions   23 years      
Letter of credit $ 121,400 $ 119,700      
Annual risk free rate 2.28%        
Increase (decrease) through transfers and other changes, other provisions $ 41,100        
Bottom of range [member]          
Provisions and contingent liabilities          
Discount rate used to reflect time value of money for provisions 1.79% 1.98%      
Period Used To Reflect Time Value Of Money For Provisions 1 year 1 year      
Top of range [member]          
Provisions and contingent liabilities          
Discount rate used to reflect time value of money for provisions 3.12% 4.74%      
Period Used To Reflect Time Value Of Money For Provisions 22 years        
Provision for remediation and mine closure [Member]          
Provisions and contingent liabilities          
Other non-current provisions $ 195,900 $ 131,888 $ 156,859 $ 153,313  
Future value of non current provisions 374,400 $ 374,400 $ 374,400    
Annual risk free rate   2.99% 2.73%    
Increase (decrease) through transfers and other changes, other provisions 41,130 $ (32,017) $ (3,710)    
Provision for royalties and mining tax [Member]          
Provisions and contingent liabilities          
Interest and penalties associated with disputed mining royalties   70,000      
Interest and penalties associated with income tax related to disputed mining royalties 42,100 41,100      
Interest and penalties associated with ITAN 6,700 9,800      
Interest and penalties associated with SRF 1,900        
Interest and penalties associated with special mining tax   50,800      
Net asset tax included in provisions 12,100 19,600      
La Joya [Member] | Irrigation Project [Member] | Provision for social commitments [Member]          
Provisions and contingent liabilities          
Other provisions 4,400        
Alata-Congata Road [Member] | Repaving Project [Member] | Provision for social commitments [Member]          
Provisions and contingent liabilities          
Other provisions 6,300        
Minera Yanacocha SRL and subsidiary [Member]          
Provisions and contingent liabilities          
Current provisions 90,940 41,154      
Provision for closure of mining units and exploration projects 1,608,380 1,294,464 1,234,731   $ 1,012,888
Other provisions 2,484 2,785      
Non-current provisions 1,587,856 1,293,149      
Increase in reclamation liability 301,000 44,000 206,000    
Increase in recorded asset retirement cost 159,000 27,200 97,000    
Non-cash charge to reclamation expense $ 142,000 $ 16,300 $ 124,100    
Minera Yanacocha SRL and subsidiary [Member] | Bottom of range [member]          
Provisions and contingent liabilities          
Discount rates used in the calculation of the provision 0.20% 0.20% 0.20%    
Minera Yanacocha SRL and subsidiary [Member] | Top of range [member]          
Provisions and contingent liabilities          
Discount rates used in the calculation of the provision 0.30% 0.30% 0.30%    
Sociedad Minera Cerro Verde Saa [Member]          
Provisions and contingent liabilities          
Other non-current provisions $ 278,419 $ 342,331      
Sociedad Minera Cerro Verde Saa [Member] | Provision for social commitments [Member]          
Provisions and contingent liabilities          
Other non-current provisions 3,046 8,111      
Sociedad Minera Cerro Verde Saa [Member] | Provision for remediation and mine closure [Member]          
Provisions and contingent liabilities          
Other non-current provisions 195,659 131,888      
Sociedad Minera Cerro Verde Saa [Member] | Provision for royalties and mining tax [Member]          
Provisions and contingent liabilities          
Other non-current provisions 62,797 $ 191,299      
Sociedad Minera Cerro Verde Saa [Member] | Ministry of Energy and Mines [Member]          
Provisions and contingent liabilities          
Letter of credit 51,000        
INGEMMET          
Provisions and contingent liabilities          
Fines and penalties 6,800        
INGEMMET | Sociedad Minera Cerro Verde Saa [Member] | Services and freight not invoiced          
Provisions and contingent liabilities          
Current provisions 20,900        
Fines and penalties $ 7,000