Note 13 - Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Loss carryforwards U.S. - Federal/States	$ 1,801,000	$ 6,598,000
Asset retirement obligations	6,428,000	6,359,000
Accrued expenses	3,857,000	3,257,000
Stock-based compensation	2,916,000	2,249,000
Total deferred tax assets	15,002,000	18,463,000
Valuation allowances	0	0
Deferred tax liabilities:
Depreciation & amortization	(69,354,000)	(54,100,000)
Net deferred tax liabilities	$ (54,352,000)	$ (35,637,000)