Note 5 - Oil and Gas Leases - Company's Royalty and Working Interests Share (Details)	12 Months Ended
	Dec. 31, 2021 Mcfe Boe	Dec. 31, 2020 Mcfe Boe
Natural Gas and Natural Gas Liquids [Member]
Net oil or gas produced (Thousand Cubic Foot Equivalent) | Mcfe	10,410	12,376
Crude Oil and Natural Gas Liquids (NGL) [Member]
Net oil or gas produced (Thousand Cubic Foot Equivalent) | Boe	5,072	5,043