Note 12 - Business Segment and Geographic Financial Data - Geographic Segment Financial Data (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenues	$ 27,081	$ 26,941
Assets	50,388	50,124
UNITED STATES
Revenues	21,062	20,311
Assets	46,487	47,007
Non-US [Member]
Revenues	6,019	6,630
Assets	$ 3,901	$ 3,117