Note 8 - Leases - Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Other Assets [Member]
Operating lease right-of-use assets	$ 481	$ 534
Accrued Liabilities [Member]
Current operating lease liabilities	234	225
Other Noncurrent Liabilities [Member]
Noncurrent operating lease liabilities	265	327
Accrued Liabilities and Other Noncurrent Liabilities [Member]
Operating Lease, Liability, Total	$ 499	$ 552