SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Property, Plant and Equipment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Building
Property, Plant and Equipment [Line Items]
Property, plant, equipment and mine development, useful life	40 years
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant, equipment and mine development, useful life	3 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant, equipment and mine development, useful life	30 years
Mobile equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant, equipment and mine development, useful life		3 years
Mobile equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant, equipment and mine development, useful life		30 years
United States oil and gas operations
Property, Plant and Equipment [Line Items]
Interest Costs Capitalized			$ 7
United States oil and gas operations | Oil and Gas Properties [Member]
Property, Plant and Equipment [Line Items]
Interest Costs Capitalized			$ 7