Note 4 - Loans - Nonaccrual Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Nonaccrual loans	$ 8,098		$ 8,098		$ 5,616
Interest income, net of tax	108	$ 115	238	$ 484
Commercial Portfolio Segment [Member]
Nonaccrual loans	1,549		1,549		61
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Nonaccrual loans	1,062		1,062		0
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Nonaccrual loans	3,750		3,750		3,103
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Nonaccrual loans	1,574		1,574		2,221
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Nonaccrual loans	145		145		191
Consumer Portfolio Segment [Member]
Nonaccrual loans	$ 18		$ 18		$ 40