PROPERTY, PLANT AND EQUIPMENT - Impairment of Property, Plant and Equipment (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 22, 2021 a
Property, Plant and Equipment [Line Items]
Land grant		$ 1,378
Impairment	$ 5,200	0	$ 5,200
Alabama Graphite
Property, Plant and Equipment [Line Items]
Acres of land under lease | a				70
Term of lease				10 years
Land grant		$ 1,400
Kingsville Dome project
Property, Plant and Equipment [Line Items]
Impairment			101
Rosita Project
Property, Plant and Equipment [Line Items]
Impairment			1,161
Cebolleta/Juan Tafoya Property
Property, Plant and Equipment [Line Items]
Impairment			$ 3,938