Note 11 - Assets and Liabilities Measured and Reported at Fair Value - Assets Measured at Fair Value on a Non-recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Other real estate owned	$ (0)	$ 22
Fair Value, Nonrecurring [Member]
Collateral dependent loans	0
Collateral dependent loans	0
Other real estate owned	0		$ 0
Other real estate owned	0	0
Impaired loans			0
Impaired loans		$ (3)
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Collateral dependent loans	0
Other real estate owned	0		0
Impaired loans			0
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Collateral dependent loans	778
Other real estate owned	493		493
Impaired loans			7,253
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Collateral dependent loans	778
Other real estate owned	$ 493		493
Impaired loans			$ 7,253