Note 3 - Loans and Allowance for Credit Losses - Nonperforming Loans (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Loans past due 90 days or more still accruing interest	$ 0	$ 0
Nonaccrual loans	5,889,000	7,728,000
Commercial Portfolio Segment [Member]
Loans past due 90 days or more still accruing interest	0	0
Nonaccrual loans	4,026,000	6,272,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans past due 90 days or more still accruing interest	0	0
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Retail Portfolio Segment [Member]
Loans past due 90 days or more still accruing interest	0	0
Nonaccrual loans	1,863,000	1,456,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Loans past due 90 days or more still accruing interest	0	0
Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due 90 days or more still accruing interest	0	0
Nonperforming Financial Instruments [Member]
Loans past due 90 days or more still accruing interest	0	0
Nonaccrual loans	5,889,000	7,728,000
Total nonperforming loans	5,889,000	7,728,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Total nonperforming loans	4,026,000	6,272,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Total nonperforming loans	3,288,000	6,024,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Total nonperforming loans	0	0
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Total nonperforming loans	738,000	248,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Total nonperforming loans	0	0
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Total nonperforming loans	0	0
Nonperforming Financial Instruments [Member] | Retail Portfolio Segment [Member]
Total nonperforming loans	1,863,000	1,456,000
Nonperforming Financial Instruments [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Total nonperforming loans	1,863,000	1,456,000
Nonperforming Financial Instruments [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Total nonperforming loans	$ 0	$ 0