Note 5 - Premises and Equipment, Net (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Leases, Future Minimum Payments Due, Total	$ 3.8	$ 3.0
Operating Leases, Future Minimum Payments Due, Next Twelve Months	0.6	0.4
Operating Leases, Future Minimum Payments, Due in Two and Three Years, Total	1.1	0.7
Operating Leases, Future Minimum Payments, Due in Four and Five Years, Total	0.9	0.5
Operating Leases, Future Minimum Payments, Due Thereafter	1.2	1.4
Depreciation, Total	$ 3.9	$ 3.6	$ 3.0