Note 11 - Business Segment Information - Revenue by Business Segment Sector (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues	$ 32,126	$ 26,770	$ 62,499	$ 52,743
Commercial [Member]
Revenues	$ 24,682	$ 16,011	$ 47,276	$ 30,356
Revenue, percentage	77.00%	60.00%	76.00%	58.00%
Government & Defense [Member]
Revenues	$ 7,444	$ 10,759	$ 15,223	$ 22,387
Revenue, percentage	23.00%	40.00%	24.00%	42.00%
Battery & Energy Products Segment [Member]
Revenues	$ 30,140	$ 22,875	$ 59,290	$ 44,986
Battery & Energy Products Segment [Member] | Commercial [Member]
Revenues	24,682	16,011	47,276	30,356
Battery & Energy Products Segment [Member] | Government & Defense [Member]
Revenues	5,458	6,864	12,014	14,630
Communications Systems Segment [Member]
Revenues	1,986	3,895	3,209	7,757
Communications Systems Segment [Member] | Commercial [Member]
Revenues	0	0	0	0
Communications Systems Segment [Member] | Government & Defense [Member]
Revenues	$ 1,986	$ 3,895	$ 3,209	$ 7,757