Note 20 - Assets and Liabilities Measured and Reported at Fair Value - Assets Measured at Fair Value on a Non-recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other real estate owned, gain (loss)	$ (73)	$ (7)	$ 102
Fair Value, Nonrecurring [Member]
Collateral dependent loans	0	0
Other real estate owned	0	0
Other real estate owned, gain (loss)	52	70
Collateral dependent loans, gain (loss)		20
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Collateral dependent loans	0	0
Other real estate owned	0	0
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Collateral dependent loans	7,546	7,253
Other real estate owned	281	493
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Collateral dependent loans	7,546	7,253
Other real estate owned	$ 281	$ 493