Note 5 - Loans - Loans Modified as TDRs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018
Number of contracts	10	0
Pre-modification outstanding recorded investment	$ 1,817
Post-modification outstanding recorded investment	1,865
Extended Maturity [Member]
Pre-modification outstanding recorded investment	1,389
Extended Maturity and Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment	178
Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment	42
Forbearance [Member]
Pre-modification outstanding recorded investment	$ 208
Residential Portfolio Segment [Member]
Number of contracts	4
Pre-modification outstanding recorded investment	$ 274
Post-modification outstanding recorded investment	289
Residential Portfolio Segment [Member] | Extended Maturity [Member]
Pre-modification outstanding recorded investment	24
Residential Portfolio Segment [Member] | Extended Maturity and Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
Residential Portfolio Segment [Member] | Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment	42
Residential Portfolio Segment [Member] | Forbearance [Member]
Pre-modification outstanding recorded investment	$ 208
Commercial Real Estate Portfolio Segment [Member]
Number of contracts	2
Pre-modification outstanding recorded investment	$ 610
Post-modification outstanding recorded investment	644
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity [Member]
Pre-modification outstanding recorded investment	432
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity and Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment	178
Commercial Real Estate Portfolio Segment [Member] | Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
Commercial Real Estate Portfolio Segment [Member] | Forbearance [Member]
Pre-modification outstanding recorded investment
Construction, Land Acquisition and Development [Member]
Number of contracts
Pre-modification outstanding recorded investment
Post-modification outstanding recorded investment
Construction, Land Acquisition and Development [Member] | Extended Maturity [Member]
Pre-modification outstanding recorded investment
Construction, Land Acquisition and Development [Member] | Extended Maturity and Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
Construction, Land Acquisition and Development [Member] | Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
Construction, Land Acquisition and Development [Member] | Forbearance [Member]
Pre-modification outstanding recorded investment
Commercial and Industrial [Member]
Number of contracts	4
Pre-modification outstanding recorded investment	$ 933
Post-modification outstanding recorded investment	932
Commercial and Industrial [Member] | Extended Maturity [Member]
Pre-modification outstanding recorded investment	933
Commercial and Industrial [Member] | Extended Maturity and Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
Commercial and Industrial [Member] | Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
Commercial and Industrial [Member] | Forbearance [Member]
Pre-modification outstanding recorded investment
Consumer Portfolio Segment [Member]
Number of contracts
Pre-modification outstanding recorded investment
Post-modification outstanding recorded investment
Consumer Portfolio Segment [Member] | Extended Maturity [Member]
Pre-modification outstanding recorded investment
Consumer Portfolio Segment [Member] | Extended Maturity and Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
Consumer Portfolio Segment [Member] | Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
Consumer Portfolio Segment [Member] | Forbearance [Member]
Pre-modification outstanding recorded investment
State and Political Subdivisions [Member]
Number of contracts
Pre-modification outstanding recorded investment
Post-modification outstanding recorded investment
State and Political Subdivisions [Member] | Extended Maturity [Member]
Pre-modification outstanding recorded investment
State and Political Subdivisions [Member] | Extended Maturity and Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
State and Political Subdivisions [Member] | Capitalization of Taxes [Member]
Pre-modification outstanding recorded investment
State and Political Subdivisions [Member] | Forbearance [Member]
Pre-modification outstanding recorded investment