Note 6 - Summary of Quantitative Attributes of Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Lease cost
Operating lease cost	$ 628	$ 672
Total lease cost	628	672
Cash paid for amounts included in the measurement of lease liabilities:
Cashflows from operating leases	631	654	$ 583
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 698	$ 1,086	$ 2,407
Weighted average remaining lease terms:
Operating leases	13 years 8 months 12 days	14 years 1 month 6 days
Weighted average discount rates:
Operating leases	2.78%	2.96%