Note 14 - Financial Instruments - Significant Unobservable Inputs Used Fair Value Measurements (Details) $ in Thousands	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Minimum [Member] | Measurement Input, Discount Rate [Member]
Impaired loans, significant unobservable inputs	0
Other real estate owned, significant unobservable inputs	0
Maximum [Member] | Measurement Input, Discount Rate [Member]
Impaired loans, significant unobservable inputs	0.1
Other real estate owned, significant unobservable inputs	0
Impaired Loans [Member]
Assets at fair value	$ 203	$ 371
Other Real Estate Owned [Member]
Assets at fair value		$ 753