Note 13 - Segment Information - Identifiable Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Identifiable Assets	$ 134,583	$ 110,066
Corporate, Non-Segment [Member]
Identifiable Assets	28,143	4,017
Electronic Test [Member] | Operating Segments [Member]
Identifiable Assets	32,406	31,143
Environmental Technologies [Member] | Operating Segments [Member]
Identifiable Assets	17,349	18,040
Process Technologies [Member] | Operating Segments [Member]
Identifiable Assets	$ 56,685	$ 56,866