Note 11 - Business Segment and Geographic Financial Data - Geographic Segment Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Revenues	$ 5,558	$ 7,042	$ 11,940	$ 11,999
Assets	47,003		47,003		$ 48,797
UNITED STATES
Revenues	4,442	4,471	9,801	8,066
Assets	44,130		44,130		44,430
Non-US [Member]
Revenues	1,116	$ 2,571	2,139	$ 3,933
Assets	$ 2,873		$ 2,873		$ 4,367