Note 4 - Segment Information - Assets and Capital Expenditures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Assets	$ 41,850	$ 39,785
Capital expenditures	0	0
Operating Segments [Member] | Electronic Instruments [Member]
Assets	843	1,118
Capital expenditures	0	0
Operating Segments [Member] | Merchant Investment [Member]
Assets	23,530	0
Capital expenditures	0	0
Corporate, Non-Segment [Member]
Assets	17,477	38,667
Capital expenditures	$ 0	$ 0