Note 4 - Loans - Nonaccrual Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Nonaccrual loans	$ 3,813		$ 3,813		$ 7,013
Interest income, net of tax	46	$ 84	89	$ 140
Commercial Portfolio Segment [Member]
Nonaccrual loans	1,506		1,506		1,535
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Nonaccrual loans	606		606		640
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Nonaccrual loans	89		89		3,094
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Nonaccrual loans	1,463		1,463		1,585
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Nonaccrual loans	133		133		141
Consumer Portfolio Segment [Member]
Nonaccrual loans	$ 16		$ 16		$ 18