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Inventories, Including Long-Term Mill and Leach Stockpiles (Unaudited) (Details) - USD ($)
$ in Millions
Mar. 31, 2018
Dec. 31, 2017
Components of Inventories [Line Items]    
Total materials and supplies, net $ 1,335 $ 1,305
Mill stockpiles 330 360
Leach stockpiles 1,118 1,062
Total current mill and leach stockpiles 1,448 1,422
Raw materials (primarily concentrate) 284 265
Work-in-process 138 154
Finished goods 680 747
Total product inventories 1,102 1,166
Mill stockpiles 308 300
Leach stockpiles 1,079 1,109
Total long-term mill and leach stockpiles 1,387 1,409
Inventory obsolescence reserves $ 25 $ 29