Note 5 - Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Liabilities held for sale of discontinued operations, current
Share-based compensation	$ 8,966	$ 5,387
Additions to property and equipment	12,749	54,414
Discontinued Operations, Disposed of by Sale [Member] \| Cesium-131 Business [Member]
Liabilities held for sale of discontinued operations, current
Sales, net	0	2,178
Cost of sales	(332)	1,564
Gross profit	332	614
Research and development	0	69
Sales and marketing	0	941
General and administrative	0	494
(Gain) loss recognized on assets held for sale	(182)	59
Total operating expenses	(182)	1,563
Total gain (loss) from discontinued operations	$ 514	$ (949)

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Amount of gain (loss) from the difference between the sale price or salvage price and the book value of an asset that was sold or retired, and gain (loss) from the write down of assets from their carrying value to fair value.

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