XML 49 R52.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
INVENTORIES: (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Metals at average cost:      
Finished goods $ 87.2 $ 69.6  
Work-in-process 259.7 256.8  
Ore stockpiles on leach pads 358.4 328.0  
Supplies at average cost 363.2 378.3  
Total current inventory 1,068.5 1,032.7  
Inventory, long-term:      
Ore stockpiles on leach pads 1,230.3 1,177.4  
Total leaching costs added as long-term inventory of ore stockpiles in leach pads 469.0 506.6 $ 513.9
Long-term leaching inventories recognized as cost of sales $ 385.8 $ 299.4 $ 333.5