Note 11 - Business Segment and Geographic Financial Data - Geographic Segment Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Revenues	$ 7,287	$ 5,535
Assets	50,282		$ 50,124
UNITED STATES
Revenues	5,981	3,688
Assets	46,893		47,007
Non-US [Member]
Revenues	1,306	$ 1,847
Assets	$ 3,389		$ 3,117