LEASES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 63	$ 87
Lease liability	65
Operating lease liability, current	56	$ 91
Total lease payments	$ 65
Lease not yet commenced, Term	5 years
Net present value of lease not yet commenced	$ 1,100
Centennial, Colorado
Lessee, Lease, Description [Line Items]
Total lease payments	$ 100
Corporate office
Lessee, Lease, Description [Line Items]
Variable lease terms	Because these amounts are variable from year to year and not specifically set in the lease terms, they are not included in the measurement of the right-of-use asset and related lease liability, but rather expensed in the period incurred.  The remaining lease terms for the office equipment leases ranges from 3.1 to 4.3 years.
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Option to extend, renewal term	3 years
Minimum
Lessee, Lease, Description [Line Items]
Lease term using a discount rate	3.00%
Minimum | Corporate offices, storage space and equipment
Lessee, Lease, Description [Line Items]
Remaining lease term	3 months 18 days
Minimum | Corporate office
Lessee, Lease, Description [Line Items]
Remaining lease term	3 years 1 month 6 days
Maximum
Lessee, Lease, Description [Line Items]
Lease term using a discount rate	9.50%
Maximum | Corporate office
Lessee, Lease, Description [Line Items]
Remaining lease term	4 years 3 months 18 days
Maximum | Land used in exploration and mining activities, office equipment, machinery, office space, storage and other
Lessee, Lease, Description [Line Items]
Term of contract	1 year