Note 12 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
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)	7,663,000	$ 14,250,000	17,602,000	$ 16,547,000
Deferred Income Tax Liabilities, Net	250,000,000		250,000,000		232,398,000
Share Repurchase Program, Excise Tax			0		351,000
Texas Margin Tax [Member]
Income Tax Expense (Benefit)			0	$ 301,000
Texas Margin Tax [Member] | State and Local Jurisdiction [Member]
Deferred Income Tax Liabilities, Net	9,400,000		9,400,000		$ 8,600,000
Cumulative Effect, Period of Adoption, Adjustment [Member]
Deferred Tax Assets, Gross	$ 3,000,000		3,000,000
Income Tax Expense (Benefit)			$ 1,000,000