Note 4 - Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Net Carrying Amount	$ 18,046	$ 18,559
Finite-lived, Gross Carrying Amount	20,691	20,660
Finite-lived, Accumulated Amortization	11,020	10,470
Net Carrying Amount, finite-lived	9,671	10,190
Indefinite-lived, Gross Carrying Amount	8,375	8,369
Net Carrying Amount, indefinite-lived	8,375	8,369
Intangible Assets, Gross Carrying Amount	29,066	29,029
Net Carrying Amount	18,046	18,559
Trademarks [Member]
Indefinite-lived, Gross Carrying Amount	8,375	8,369
Net Carrying Amount, indefinite-lived	8,375	8,369
Customer Relationships [Member]
Finite-lived, Gross Carrying Amount	16,334	16,313
Finite-lived, Accumulated Amortization	8,431	7,990
Net Carrying Amount, finite-lived	7,903	8,323
Patented Technology [Member]
Finite-lived, Gross Carrying Amount	2,863	2,855
Finite-lived, Accumulated Amortization	1,095	988
Net Carrying Amount, finite-lived	1,768	1,867
Patents [Member]
Finite-lived, Gross Carrying Amount	590	590
Finite-lived, Accumulated Amortization	590	590
Net Carrying Amount, finite-lived	0	0
Customer Backlog [Member]
Finite-lived, Gross Carrying Amount	494	492
Finite-lived, Accumulated Amortization	494	492
Net Carrying Amount, finite-lived	0	0
Computer Software, Intangible Asset [Member]
Finite-lived, Gross Carrying Amount	270	270
Finite-lived, Accumulated Amortization	270	270
Net Carrying Amount, finite-lived	0	0
Trade Names [Member]
Finite-lived, Gross Carrying Amount	140	140
Finite-lived, Accumulated Amortization	140	140
Net Carrying Amount, finite-lived	0	0
Electronic Test [Member]
Net Carrying Amount	4,019	4,139
Net Carrying Amount	4,019	4,139
Environmental Technologies [Member]
Net Carrying Amount	823	832
Net Carrying Amount	823	832
Process Technologies [Member]
Net Carrying Amount	13,204	13,588
Net Carrying Amount	$ 13,204	$ 13,588