Note 7 - Derivatives and Hedging Activities - Changes in Fair Values of Derivative Financial Instruments (Details) - Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Unrealized loss at beginning of period, net of tax	$ (1,276)	$ (805)
Amount of loss recognized in other comprehensive income, net of tax	(3,061)	(1,073)
Unrealized loss at end of period, net of tax	(3,915)	(1,276)
Hedge Ineffectiveness [Member] | Noninterest Expense [Member]
Amount reclassified from accumulated other comprehensive income		27
Caplet Amortization [Member]
Amount reclassified from accumulated other comprehensive income	$ 422	$ 575