Note 13 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Deferred Tax Assets, Valuation Allowance, Total	$ 0		$ 0
Income Tax Expense (Benefit), Total	(312)	$ 1,115
Deferred Income Tax Liabilities, Net	55,490		55,802
State and Local Jurisdiction [Member] | Texas Margin Tax [Member]
Deferred Income Tax Liabilities, Net	1,700		$ 1,800
Cumulative Effect, Period of Adoption, Adjustment [Member]
Deferred Tax Assets, Gross, Total	(3,400)
Income Tax Expense (Benefit), Total	$ 3,400