Note 5 - Supplemental Balance Sheet Information - Summary of Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)
Goodwill balance	$ 38,068
Measurement period adjustment (1)	(30)	[1]
Effect of foreign currency translation	(112)
Goodwill balance	37,926
Battery & Energy Products Segment [Member]
Goodwill balance	26,575
Measurement period adjustment (1)	(30)	[1]
Effect of foreign currency translation	(112)
Goodwill balance	26,433
Communications Systems Segment [Member]
Goodwill balance	11,493
Measurement period adjustment (1)	0	[1]
Effect of foreign currency translation	0
Goodwill balance	$ 11,493

[1] Change for measurement period adjustment related to Excell Acquisition (Note 2).