Note 6 - Fair Value of Financial Instruments - Changes in Derivative Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024
Measurement at December 31, 2024	$ 101	$ 224	$ 411	$ 597
Change in fair value	20	(123)	(42)	(186)
Measurement at March 31, 2025	121	101	369	411
Notes Warrants [Member]
Measurement at December 31, 2024	90	197	362	334
Change in fair value	17	(107)	(24)	28
Measurement at March 31, 2025	107	90	338	362
Additional Warrants [Member]
Measurement at December 31, 2024	11	27	49	263
Change in fair value	3	(16)	(18)	(214)
Measurement at March 31, 2025	$ 14	$ 11	$ 31	$ 49