Note 5 - Loans - Newly Restructured Loans and Types of Modifications (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Financing receivable modifications	$ 67
Interest Rate Reduction and Extension of Maturity [Member]
Financing receivable modifications	20
Rate Reduction and Payment Deferral [Member]
Financing receivable modifications
Extended Maturity [Member]
Financing receivable modifications	47
Commercial Portfolio Segment [Member]
Financing receivable modifications	47
Commercial Portfolio Segment [Member] | Interest Rate Reduction and Extension of Maturity [Member]
Financing receivable modifications
Commercial Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing receivable modifications
Commercial Portfolio Segment [Member] | Extended Maturity [Member]
Financing receivable modifications	47
Consumer Portfolio Segment [Member]
Financing receivable modifications	20
Consumer Portfolio Segment [Member] | Interest Rate Reduction and Extension of Maturity [Member]
Financing receivable modifications	20
Consumer Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing receivable modifications
Consumer Portfolio Segment [Member] | Extended Maturity [Member]
Financing receivable modifications