Note 8 - Operating Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Weighted-average remaining lease term (years) (Year)	4 years 4 months 24 days	4 years 6 months
Weighted-average discount rate	4.50%	4.50%
Other Noncurrent Assets [Member]
Operating lease right-of-use asset	$ 2,401	$ 2,581
Accrued Expenses and Other Current Liabilities [Member]
Current operating lease liability	869	867
Other Noncurrent Liabilities [Member]
Operating lease liability, net of current portion	1,558	1,743
Accrued Expenses and Other Current Liabilites and Other Noncurrent Liabilities [Member]
Total operating lease liability	$ 2,427	$ 2,610