PROPERTY, PLANT AND EQUIPMENT, NET - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Net carrying amounts of mineral deposits	$ 231.7	$ 238.9
Depreciation, depletion and amortization	93.2	91.8	$ 67.8
Property, Plant and Equipment
Property, Plant and Equipment [Line Items]
Depreciation, depletion and amortization	$ 69.3	$ 67.9	$ 47.1