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		6 Months Ended			12 Months Ended
		Jun. 30, 2022		Jun. 30, 2021	Dec. 31, 2021
Loans past due 90 days or more and still accruing		$ 7		$ 28	$ 90
Ratio of loans past due 90 days or more and still accruing to loans, net of unearned income and deferred fees and costs		0.00%		0.00%	0.01%
Accruing restructured loans		$ 2,998		$ 3,011	$ 3,005
Impaired loans:
Impaired loans with no valuation allowance		5,809	[1]	6,774	5,878	[1]
Impaired loans with a valuation allowance		0		0	0	[1]
Total impaired loans		5,809	[1]	6,774	5,878	[1]
Valuation allowance		0		0	0
Impaired loans, net of allowance		5,809		6,774	5,878
Average recorded investment in impaired loans(1)	[1]	5,820		6,796	5,901
Interest income recognized on impaired loans, after designation as impaired		43		105	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.