Note 13 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Deferred Tax Assets, Valuation Allowance	$ 0	$ 0
Income Tax Expense (Benefit), Total	65,905	75,361	$ 16,904
Deferred Income Tax Liabilities, Net	197,068	131,164
State and Local Jurisdiction [Member] | Texas Margin Tax [Member]
Deferred Income Tax Liabilities, Net	7,100	$ 4,100
Cumulative Effect, Period of Adoption, Adjustment [Member]
Income Tax Expense (Benefit), Total	$ 3,400