INVENTORIES, INCLUDING LONG-TERM MILL AND LEACH STOCKPILES (Components of Inventories) (Details) - USD ($) $ in Millions		3 Months Ended				12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of Inventories [Line Items]
Total material and supplies, net	[1]	$ 1,869				$ 1,869	$ 1,886
Total current mill and leach stockpiles		1,724				1,724	1,914
Raw materials (primarily concentrate)		220				220	288
Work-in-process		108				108	174
Finished goods		867				867	1,099
Total product inventories		1,195				1,195	1,561
Total long-term inventories		2,271				2,271	2,179
Inventory obsolescence reserves		29				29	20
Copper and Molybdenum Inventory Adjustments		184	$ 91	$ 59	$ 4	338	6	$ 3
Current [Member]
Components of Inventories [Line Items]
Mill Stockpiles		137				137	86
Leach stockpiles		1,587				1,587	1,828
Total current mill and leach stockpiles		1,724				1,724	1,914
Long-Term [Member]
Components of Inventories [Line Items]
Mill Stockpiles		480				480	360
Leach stockpiles		1,791				1,791	1,819
Total long-term inventories	[2]	$ 2,271				2,271	$ 2,179
Copper [Member]
Components of Inventories [Line Items]
Copper and Molybdenum Inventory Adjustments						215
Molybdenum [Member]
Components of Inventories [Line Items]
Copper and Molybdenum Inventory Adjustments						$ 123

[1] Materials and supplies inventory was net of obsolescence reserves totaling $29 million at December 31, 2015, and $20 million at December 31, 2014.

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