Note 17 - Segment Information - Identifiable Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Identifiable Assets	$ 134,829	$ 110,066
Capital expenditures	1,291	1,365
Electronic Test [Member]
Identifiable Assets	32,505	31,143
Capital expenditures	599	80
Environmental Technologies [Member]
Identifiable Assets	16,772	18,040
Capital expenditures	495	368
Process Technologies [Member]
Identifiable Assets	56,842	56,866
Capital expenditures	170	543
Corporate Segment [Member]
Identifiable Assets	28,710	4,017
Capital expenditures	$ 27	$ 374