XML 157 R132.htm IDEA: XBRL DOCUMENT v3.21.1
Inventories, net (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Inventory, net        
Finished goods $ 2,525 $ 2,084 $ 4,640  
Products in process [1] 52,619 47,652    
Spare parts and supplies 76,937 74,033    
Inventory gross 132,081 123,769    
Provision for impairment of value of inventory (31,117) (25,402)    
Finished goods [Abstract]        
Current portion 77,327 97,973    
Inventories, net 23,637 394    
Inventories 100,964 98,367    
Minera Yanacocha SRL and subsidiary [Member]        
Inventory, net        
Inventory gross 58,892 60,343    
Allowance for obsolescence of materials and supplies (b) (6,595) (6,098) $ (7,515) $ (7,076)
Finished goods [Abstract]        
Current portion 52,297 54,245    
Inventories 52,297 54,245    
Minera Yanacocha SRL and subsidiary [Member] | Precious metals [Member]        
Inventory, net        
Inventory gross 12,559 8,021    
Minera Yanacocha SRL and subsidiary [Member] | Leach in circuit [Member]        
Inventory, net        
Inventory gross 3,117 5,158    
Minera Yanacocha SRL and subsidiary [Member] | Mill in circuit [Member]        
Inventory, net        
Inventory gross 2,093 1,332    
Minera Yanacocha SRL and subsidiary [Member] | Supplies        
Inventory, net        
Inventory gross 41,123 45,832    
Sociedad Minera Cerro Verde S.A.A. [Member]        
Inventory, net        
Products in process [2] 176,813 173,190    
Finished goods [Abstract]        
Copper cathode 3,826 6,321    
Copper concentrate 16,563 23,890    
Molybdenum concentrate 700 1,268    
Less: Provision for obsolescence of materials and supplies (104) (507)    
Current portion 566,794 552,197    
Inventories, net [2] 301,075 255,123    
Inventories 867,869 807,320    
Materials and supplies $ 368,996 $ 348,035    
[1] Products in process include mainly to mineral in process of El Brocal for 1,527,521 Dried Metric Ton (DMT) amounting to US$32.2 million (1,592,905 DMT amounting to US$31.2 million as of December 31, 2019).
[2] WIP inventories represent mill and leach stockpiles, which contain higher grade ores (mill stockpiles) and medium and lower grade ores (leach stockpiles) that have been extracted from the open pit and are available for copper recovery. Based on the future mine plan production, the Company identifies the portion of inventory that is classified as current or long-term. For mill stockpiles, recovery is through milling and concentrating. For leach stockpiles, recovery is through exposure to acidic solutions that dissolve copper and deliver it in a solution to extraction processing facilities.