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

3 Months Ended

Mar. 31, 2020

Inventory Disclosure [Abstract]

Schedule of Inventory

The components of inventories follow (in millions):

	March 31, 2020		December 31, 2019
Current inventories:
Total materials and supplies, neta	$	1,614	$	1,649
Mill stockpiles	$	158	$	220
Leach stockpiles	948		923
Total current mill and leach stockpiles	$	1,106	$	1,143
Raw materials (primarily concentrate)	$	209	$	318
Work-in-process	106		124
Finished goods	819		839
Total product	$	1,134	$	1,281
Long-term inventories:
Mill stockpiles	$	193	$	181
Leach stockpiles	1,079		1,244
Total long-term mill and leach stockpilesb	$	1,272	$	1,425

a. Materials and supplies inventory was net of obsolescence reserves totaling $25 million at March 31, 2020, and $24 million at December 31, 2019.

b.

Estimated metals in stockpiles not expected to be recovered within the next 12 months.