Note 11 - Business Segment and Geographic Financial Data - Geographic Segment Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Revenues	$ 8,017	$ 7,559	$ 19,920	$ 17,810
Assets	49,682		49,682		$ 49,974
UNITED STATES
Revenues	6,972	6,049	14,939	15,100
Assets	47,170		47,170		46,271
Non-US [Member]
Revenues	1,045	$ 1,510	4,981	$ 2,710
Assets	$ 2,512		$ 2,512		$ 3,703