Inventories, Including Long-Term Mill and Leach Stockpiles (Unaudited)

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Inventories, Including Long-Term Mill and Leach Stockpiles

INVENTORIES, INCLUDING LONG-TERM MILL AND LEACH STOCKPILES

The components of inventories follow (in millions):

	March 31, 2018		December 31, 2017
Current inventories:
Total materials and supplies, neta	$	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
Long-term inventories:
Mill stockpiles	$	308	$	300
Leach stockpiles	1,079		1,109
Total long-term mill and leach stockpiles	$	1,387	$	1,409

a. Materials and supplies inventory was net of obsolescence reserves totaling $25 million at March 31, 2018, and $29 million at December 31, 2017.