Note 6 - Summary of Quantitative Attributes of Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Lease cost
Operating lease cost	$ 609	$ 628
Total lease cost	609	628
Cash paid for amounts included in the measurement of lease liabilities:
Cashflows from operating leases	620	631	$ 654
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 43	$ 698	$ 1,086
Weighted average remaining lease terms:
Operating leases	13 years 9 months 18 days	13 years 8 months 12 days
Weighted average discount rates:
Operating leases	2.78%	2.78%