Note 14 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Net revenues	$ 29,824	$ 31,919
Earnings before income tax expense	787	3,394
Acquired intangible amortization	(595)	(544)
Interest expense	(140)	(182)
Other income (expense)	435	58
Operating Segments [Member]
Net revenues	29,824	31,919
Earnings before income tax expense	3,789	6,267
Operating Segments [Member] | Electronic Test [Member]
Net revenues	11,116	10,371
Earnings before income tax expense	1,813	2,578
Operating Segments [Member] | Environmental Technologies [Member]
Net revenues	6,828	8,042
Earnings before income tax expense	15	1,013
Operating Segments [Member] | Process Technologies [Member]
Net revenues	11,880	13,506
Earnings before income tax expense	1,961	2,676
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Earnings before income tax expense	$ (2,702)	$ (2,205)