Segment Information - Summary of segment information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Australia segment operating income (expense):
Depreciation and amortization	$ (22)	$ (12)
Corporate administration	(1,298)	(1,256)
Gain on sale of plant and equipment		802
Total operating expense, net	(2,858)	(1,218)
Non-operating income:
Interest income	169	103
Other income (expense)	(19)	42
Total non-operating income	150	145
Net loss	(2,708)	(1,073)
Australia segment long-lived assets	1,633		$ 1,471
Corporate
Australia segment operating income (expense):
Corporate administration	(1,298)	(1,256)
Gain on sale of plant and equipment		802
Australia segment
Non-operating income:
Australia segment expenditures: mineral property and capital assets	184	555
Australia segment long-lived assets	1,564		$ 1,402
Australia segment | Operating segments
Australia segment operating income (expense):
Employee Compensation	(544)	(431)
2025 feasibility study and related costs	(739)
Drilling and related costs	(24)	(414)
Capitalized development costs	150	504
Project Programs	(52)	(126)
Site holding	(176)	(118)
Administrative	(85)	(77)
Consulting & contract services	(27)	(35)
Power	(41)	(55)
Depreciation and amortization	(22)	(12)
Total operating expense, net	$ (1,560)	$ (764)