Note 6 - Income Taxes - Components of Income Tax Expense (Benefit) from Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Current income tax expense:
Federal	$ 1,842	$ 2,726
State	131	141
Total current income tax expense	1,973	2,867
Deferred income tax expense (benefit):
Federal	652	565
State	(376)	(1,613)
Total deferred income tax expense (benefit)	276	(1,048)
Change in valuation allowance	1	20
Total income tax expense	$ 2,250	$ 1,839