Note 6 - Income Taxes - Components of Income Tax Expense (Benefit) from Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Current income tax expense:
Federal	$ 3,493	$ 1,842
State	522	131
Total current income tax expense	4,015	1,973
Deferred income tax expense (benefit):
Federal	837	652
State	609	(376)
Total deferred income tax expense (benefit)	1,446	276
Change in valuation allowance	0	1
Total income tax expense	$ 5,461	$ 2,250