Note 2 - Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net sales	$ 18,109	$ 12,212	$ 37,570	$ 28,641
Product [Member]
Net sales	17,914	12,144	37,094	28,526
Service [Member]
Net sales	$ 195	$ 68	$ 476	$ 115