Note 2 - Basis of Presentation and Summary of Significant Accounting Policies - Other Property and Equipment, Net (Details) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Other property and equipment, net	$ 2,473,000	$ 1,600,000
Land [Member]
Other property and equipment, net	1,122,000	1,122,000
Transportation Equipment [Member]
Other property and equipment, net	609,000	202,000
Building [Member]
Other property and equipment, net	532,000	0
Leasehold Improvements [Member]
Other property and equipment, net	161,000	143,000
Technology Equipment [Member]
Other property and equipment, net	42,000	125,000
Field Equipment [Member]
Other property and equipment, net	$ 7,000	$ 8,000