Note 2 - Basis of Presentation and Summary of Significant Accounting Policies - Other Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Other property and equipment, net	$ 3,081	$ 3,201
Land [Member]
Other property and equipment, net	1,869	1,869
Transportation Equipment [Member]
Other property and equipment, net	516	620
Building [Member]
Other property and equipment, net	509	516
Leasehold Improvements [Member]
Other property and equipment, net	186	193
Field Equipment [Member]
Other property and equipment, net	1	2
Furniture and Fixtures [Member]
Other property and equipment, net	$ 0	$ 1