Note 1 - Organization and Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Total cost	$ 22,852	$ 32,109
Less accumulated depreciation	(18,243)	(26,889)
Total net book value	4,609	5,220
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	$ 2,626	2,886
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	$ 11,787	19,748
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	$ 2,099	2,954
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	$ 1,308	1,477
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	$ 32	32
Depreciable Life (Year)	5 years
Construction in Progress [Member]
Total cost	$ 0	$ 12

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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