Note 11 - Business Segment and Geographic Financial Data - Geographic Segment Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Revenues	$ 7,490	$ 7,851	$ 19,430	$ 19,850
Assets	47,913		47,913		$ 48,797
UNITED STATES
Revenues	5,626	5,453	15,427	13,519
Assets	44,917		44,917		44,430
Non-US [Member]
Revenues	1,864	$ 2,398	4,003	$ 6,331
Assets	$ 2,996		$ 2,996		$ 4,367