DISPOSITIONS AND ACQUISITIONS (Purchase Price Allocation) (Details) $ in Millions		12 Months Ended
	Dec. 21, 2018 USD ($) $ / lb $ / oz	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Income tax rate		21.00%	35.00%	35.00%
Tax Authority, In Papua, Indonesia
Business Acquisition [Line Items]
Income tax rate	25.00%
PT-FI | Rio Tinto Share In Joint Venture
Business Acquisition [Line Items]
Current assets	$ 25
Mineral reserves	3,056
Mine development, infrastructure and other	1,559
Liabilities other than taxes	(77)
Deferred income taxes, net	(1,063)
Total purchase price	$ 3,500
PT-FI | Rio Tinto Share In Joint Venture | Copper
Business Acquisition [Line Items]
Price assumption per unit (in dollars per unit) | $ / lb	3.00
PT-FI | Rio Tinto Share In Joint Venture | Gold
Business Acquisition [Line Items]
Price assumption per unit (in dollars per unit) | $ / oz	1,300