PLANT AND EQUIPMENT AND MINERAL PROPERTIES (Narrative) (Details) $ / shares in Units, $ in Thousands				3 Months Ended		12 Months Ended
	May 03, 2023 USD ($)	Feb. 14, 2023 USD ($) subsidiary $ / shares	Feb. 10, 2023 USD ($) mi purchaseAgreement mineral_concession a	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Property, Plant and Equipment [Line Items]
Depreciation expense				$ 668	$ 655
Number of purchase agreements | purchaseAgreement			2
Number Of Mineral Concessions Acquired | mineral_concession			17
Purchase Agreement, acres to purchase | a			37,300
Purchase Agreement, miles to purchase | mi			58.3
Purchase Agreement, purchase price			$ 27,500
Purchase Agreement, deposit payment			5,900
Purchase Agreement, payment due at closing			21,600
Purchase Agreement, direct deal costs			$ 1,630
Gain on sale of assets				0	116,450
Plus: release of restricted cash related to sale of assets				0	(3,475)
Additions to property, plant and equipment				4,783	2,042
Restricted Cash And Cash Equivalents Held For Sale						$ 3,590
Alta Mesa Divestiture
Property, Plant and Equipment [Line Items]
Number Of Subsidiaries Sold | subsidiary		3
Disposal Group, Including Discontinued Operation, Consideration		$ 120,000
Proceeds from Divestiture of Interest in Consolidated Subsidiaries		60,000
Disposal Group, Cash Due Prior To Closing		6,000
Disposal Group, Cash Due At Closing		54,000
Noncash or Part Noncash Divestiture, Amount of Consideration Received		$ 60,000
Convertible Note Receivable, Term		2 years
Convertible Notes Receivable, Interest Rate		8.00%
Convertible Notes Receivable, Conversion Price Per Share | $ / shares		$ 2.9103
Convertible Notes Receivable, Premium		20.00%
Convertible Notes Receivable, Conversion Limitation Per Transaction		$ 10,000
Convertible Notes Receivable, Conversion Period		30 days
Gain on sale of assets		$ 116,500
Disposal Group, Cash To Be Received		119,460
Notes Receivable, Amortized cost		59,460
Disposal Group, Including Discontinued Operation, Assets		$ 3,400
Proceeds from Sale of Productive Assets	$ 3,100
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	2,750
Additions to property, plant and equipment	500
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	$ 350
Disposal Group, Including Discontinued Operation, Property, Plant And Equipment, Usage Period	20 years
White Mesa Mill
Property, Plant and Equipment [Line Items]
Depreciation				70	$ 70
Mineral Properties [Domain]
Property, Plant and Equipment [Line Items]
Depreciation				$ 230