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Note 6 - Shareholders' Equity (Details Textual) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands			6 Months Ended
	May 07, 2025	Feb. 24, 2024	Jun. 30, 2024	Jun. 30, 2025	Feb. 25, 2025
The 2025 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)				250	250
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)				250
Share-Based Compensation Arrangement by Share-Based Payment Award, Maximum Employee Subscription Rate					15.00%
The 2018 Stock Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)	950
Registered Direct Offering [Member]
Legal Fees		$ 282
Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)			929
Common Stock [Member] \| Registered Direct Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)		929
Shares Issued, Price Per Share (in dollars per share)		$ 35
Proceeds from Issuance of Common Stock		$ 32,500