Note 5 - Income Taxes - Components of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal	$ 18,025	$ 18,872	$ 21,312
State	3,914	3,367	3,498
Total current	21,939	22,239	24,810
Deferred:
Federal	9,795	3,462	(1,557)
State	2,083	603	633
Total deferred	11,878	4,065	(924)
Total expense	$ 33,817	$ 26,304	$ 23,886