Note 2 - Summary of Significant Accounting Policies - Other Non-current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Patents	$ 34	$ 34
Security deposits	61	61
Interest receivable	7	0
Total	$ 102	$ 95

Carrying amount as of the balance sheet date of noncurrent interest earned but not received. Also called accrued interest or accrued interest receivable.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Name:	us-gaap_InterestReceivableNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant