Note 13 - Income Taxes - Reconciliation of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income taxes computed at the federal statutory rate	$ 30,701	$ 9,325	$ (1,762)
State taxes, net of federal benefits	1,422	796	(253)
State tax rate changes, net of federal benefits	(546)	(2,274)
Percentage depletion	(3,314)	(3,363)	(714)
PPP Loan forgiveness			(1,773)
Stock-based compensation	(1,499)	(194)	473
162(m) compensation limitation	3,481
Other, net	(92)	357	545
Total income tax expense (benefit), net	$ 30,153	$ 4,647	$ (3,484)