Note 1 - The Company (Additional Information) (Details) - Alexco Asset Acquisition [Member] $ / shares in Units, $ in Millions	Sep. 07, 2022 USD ($) $ / shares shares
Asset Acquisition [Line Items]
Noncash or part noncash acquisition, Interest acquired	90.10%
Noncash or part noncash acquisition, Noncash financial or equity instrument consideration, Shares issued | shares	17,992,875
Asset acquisition, Consideration transferred, Equity interest issued and issuable	$ 68.7
Asset acquisition, Consideration transferred	$ 81.5
Asset acquisition, Step acquisition, Investment held in acquiree prior to acquisition, Percentage	9.90%
Marketable Securities	$ 7.7
Asset Acquisition, Consideration Transferred, Transaction Cost	5.1
Asset acquisition, Recognized identifiable assets acquired and liabilities assumed, Deferred tax liabilities	12.9
Asset acquisition, Recognized identifiable assets acquired and liabilities assumed, Net liabilities	7.2
Advance paid to related party	25.0
Asset acquisition, Recognized identifiable assets acquired and liabilities assumed, Silver stream liability	$ 135.0
Stock issued during period shares to settle the acquired silver stream | $ / shares	$ 34,800,990
Mineral Interests [Member]
Asset Acquisition [Line Items]
Asset acquisition, Recognized identifiable assets acquired and liabilities assumed, Mineral interests	$ 236.6
Common Stock [Member]
Asset Acquisition [Line Items]
Asset Acquisition Consideration Transferred Total Non Cash Consideration	$ 76.4