DISPOSITIONS AND ACQUISITIONS (Assets Held for Sale) (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Long Lived Assets Held-for-sale [Line Items]
Net gain on sales of assets	$ 82	$ 70	$ 45	$ 11	$ 417	$ 208	$ 81
Deferred income taxes	4,032				4,210	4,032
Property, plant, equipment and mine development costs, net	28,010				29,584	28,010
Depreciation, depletion and amortization					$ 1,412	1,754	$ 1,714
Freeport Cobalt
Long Lived Assets Held-for-sale [Line Items]
Depreciation Expense on Reclassified Assets	$ 48					$ 31