Note 7 - Loans and Allowance for Credit Losses on Loans - Defaults on TDRs During Period (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Number of defaults	2	1	3
Recorded Investment at Default Date	$ 129	$ 44	$ 808
Commercial Real Estate Owner Occupied, Other [Member]
Number of defaults	0	0	1
Recorded Investment at Default Date	$ 0	$ 0	$ 361
Residential 1-4 Family Real Estate, Personal Residence [Member]
Number of defaults	1	1	1
Recorded Investment at Default Date	$ 22	$ 44	$ 48
Residential 1-4 Family Real Estate, Rental Small Loan [Member]
Number of defaults	0	0	1
Recorded Investment at Default Date	$ 0	$ 0	$ 399
Home Equity Loan [Member]
Number of defaults	1	0	0
Recorded Investment at Default Date	$ 107	$ 0	$ 0