Note 4 - Loans - Newly Restructured Loans and Types of Modifications (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Financing receivable modifications	$ 650	$ 66
Extended Maturity [Member]
Financing receivable modifications	0	66
Payment Deferral [Member]
Financing receivable modifications	650	0
Commercial Portfolio Segment [Member]
Financing receivable modifications	0	66
Commercial Portfolio Segment [Member] | Extended Maturity [Member]
Financing receivable modifications	0	66
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Financing receivable modifications	0	0
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Financing receivable modifications	650	0
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity [Member] | Commercial Owner Occupied Loan [Member]
Financing receivable modifications	0	0
Commercial Real Estate Portfolio Segment [Member] | Payment Deferral [Member] | Commercial Owner Occupied Loan [Member]
Financing receivable modifications	$ 650	$ 0