Note 12 - Federal and State Income Taxes - Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Federal income tax at statutory rate, amount	$ 21,526	$ 4,916	$ 2,124
Federal income tax at statutory rate, percent	21.00%	21.00%	21.00%
Nondeductible per diem and meals, amount	$ 0	$ 321	$ 0
Nondeductible per diem and meals, percent	0.00%	1.40%	0.00%
Other nondeductible expenses, net, amount	$ 0	$ 0	$ 342
Other nondeductible expenses, net, percent	0.00%	0.00%	3.40%
State income taxes/other, net, amount	$ 4,463	$ 345	$ (251)
State income taxes/other, net, percent	4.40%	1.50%	(2.50%)
Total federal & state income tax expense	$ 25,989	$ 5,582	$ 2,215
Total income tax (benefit) expense, percent	25.40%	23.90%	21.90%