Note 14 - Federal and State Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unrecognized tax benefits that would impact effective tax rate		$ 1,100
Unrecognized tax benefits, interest on income taxes accrued		$ 232	$ 205
Effective income tax rate		21.00%	21.00%	35.00%
Re-measurement of deferred tax asset to incorporate newly enacted tax rates	$ (2,900)			$ 2,919
Domestic Tax Authority [Member]
Deferred tax assets, operating loss carryforwards, subject to expiration		$ 3,500
State and Local Jurisdiction [Member]
Deferred tax assets, operating loss carryforwards, subject to expiration		$ 2,100