Note 1 - Organization and Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Total cost	$ 24,042	$ 23,242
Less accumulated depreciation	(18,958)	(18,703)
Total net book value	5,084	4,539
Land [Member]
Total cost	1,050	1,050
Building [Member]
Total cost	$ 3,950	3,950
Depreciable Life (Year)	39 years
Building and Leasehold Improvements [Member]
Total cost	$ 2,677	2,655
Building and Leasehold Improvements [Member] | Minimum [Member]
Depreciable Life (Year)	3 years
Building and Leasehold Improvements [Member] | Maximum [Member]
Depreciable Life (Year)	39 years
Field Equipment [Member]
Total cost	$ 13,004	12,100
Field Equipment [Member] | Minimum [Member]
Depreciable Life (Year)	3 years
Field Equipment [Member] | Maximum [Member]
Depreciable Life (Year)	4 years
Computer Equipment and Software [Member]
Total cost	$ 2,017	2,049
Computer Equipment and Software [Member] | Minimum [Member]
Depreciable Life (Year)	2 years
Computer Equipment and Software [Member] | Maximum [Member]
Depreciable Life (Year)	3 years
Furniture and Fixtures [Member]
Total cost	$ 1,305	1,307
Furniture and Fixtures [Member] | Minimum [Member]
Depreciable Life (Year)	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Depreciable Life (Year)	10 years
Vehicles [Member]
Total cost	$ 37	32
Depreciable Life (Year)	5 years
Construction in Progress [Member]
Total cost	$ 2	$ 99