Note 11 - Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Provision For Income Taxes [Abstract]
Current Federal income taxes									$ 2,789	$ 1,742	$ 3,454
Current state income taxes									380	57	124
Deferred Federal income taxes (benefits)									(207)	363	268
Deferred state income taxes (benefits)									(112)	(105)	0
Other									0	(85)	0
Net provision prior to discrete tax adjustments									2,850	1,972	3,846
DTL writeoff due to change in tax methods									0	(415)	0
Net DTA revaluation for change in tax rate under 2017 Tax Reform									0	0	2,054
Net provision	$ 623	$ 731	$ 679	$ 817	$ (339)	$ 767	$ 572	$ 557	$ 2,850	$ 1,557	$ 5,900