Note 9 - Commitments and Contingencies - Supplemental Lease Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Right-of-use asset, net and lease liabilities (in thousands)	$ 3,953		$ 3,953		$ 3,955
Lease expense	$ 348	$ 290	$ 663	$ 575
Weighted average remaining lease term (years) (Year)	3 years 9 months 18 days		3 years 9 months 18 days		3 years 6 months
Weighted average discount rate	3.40%		3.40%		4.10%
Cost of Sales [Member]
Lease expense	$ 194	224	$ 412	442
General and Administrative Expense [Member]
Lease expense	107	56	158	112
Research and Development Expense [Member]
Lease expense	$ 47	$ 10	$ 93	$ 21