Note 5 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Loans Past Due 90 Days or More and Impaired Loans (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021
Loans past due 90 days or more and still accruing	[1]	$ 8	$ 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%	0.01%
Accruing TDR loans		$ 276	$ 3,005
Impaired loans:
Impaired loans with no valuation allowance	[2]	3,032	5,878
Impaired loans with a valuation allowance	[2]	0	0
Total impaired loans	[2],[3]	3,032	5,878
Valuation allowance	[2]	0	0
Impaired loans, net of allowance		3,032	5,878
Average recorded investment in impaired loans(1)	[3]	3,047	5,901
Income recognized on impaired loans, after designation as impaired	[2]	18	137
Amount of income recognized on a cash basis		$ 0	$ 0

[1] Only classes with past due or nonaccrual loans are presented.

[2] Only classes with impaired loans are shown.

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