Note 13 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%
Deferred Tax Assets, Valuation Allowance	$ 0		$ 0		$ 0
Income Tax Expense (Benefit)	15,438,000	$ 14,100,000	31,985,000	$ 38,251,000
Deferred Income Tax Liabilities, Net	227,966,000		227,966,000		197,068,000
Texas Margin Tax [Member]
Income Tax Expense (Benefit)			519,000	$ 0
Texas Margin Tax [Member] | State and Local Jurisdiction [Member]
Deferred Income Tax Liabilities, Net	8,300,000		8,300,000		$ 6,000,000
Cumulative Effect, Period of Adoption, Adjustment [Member]
Income Tax Expense (Benefit)			1,000,000
Deferred Tax Assets, Gross	$ 3,000,000		$ 3,000,000