Note 13 - Segment Information - Identifiable Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Identifiable Assets	$ 132,857	$ 110,066
Corporate, Non-Segment [Member]
Identifiable Assets	29,428	4,017
Electronic Test [Member] | Operating Segments [Member]
Identifiable Assets	30,245	31,143
Environmental Technologies [Member] | Operating Segments [Member]
Identifiable Assets	18,080	18,040
Process Technologies [Member] | Operating Segments [Member]
Identifiable Assets	$ 55,104	$ 56,866