Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Loans Past Due 90 Days or More and Impaired Loans (Details) - USD ($) $ in Thousands		9 Months Ended			12 Months Ended
		Sep. 30, 2022		Sep. 30, 2021	Dec. 31, 2021
Loans past due 90 days or more and still accruing		$ 48		$ 62	$ 90
Ratio of loans past due 90 days or more and still accruing to loans, net of unearned income and deferred fees and costs		0.01%		0.01%	0.01%
Accruing restructured loans		$ 279		$ 3,009	$ 3,005
Impaired loans:
Impaired loans with no valuation allowance		3,049	[1]	6,084	5,878	[1]
Impaired loans with a valuation allowance		0		0	0	[1]
Total impaired loans		3,049	[1]	6,084	5,878	[1]
Valuation allowance		0		0	0
Impaired loans, net of allowance		3,049		6,084	5,878
Average recorded investment in impaired loans(1)	[1]	3,067		6,108	5,901
Interest income recognized on impaired loans, after designation as impaired		13		175	137
Amount of income recognized on a cash basis		$ 0		$ 0	$ 0

[1] Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.