Note 12 - Subsequent events (Additional Information) (Details) - Nov. 01, 2023 - Subsequent Event [Member] - Dolly Varden Silver Corporation [Member] $ in Millions	USD ($)	CAD ($)
Subsequent Event [Line Items]
Common stock value	$ 15,384,616
Total Implied Value	$ 7,300,000
Canada
Subsequent Event [Line Items]
Common stock value		$ 10

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483399/855-10-50-2

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration