Balance Sheet - Continuing Operations - Schedule of Seismic Equipment Lease Pool and Property and Equipment (Detail) - USD ($) $ in Thousands	Apr. 30, 2021	Jan. 31, 2021
Property and equipment:
Property and equipment	$ 19,184	$ 20,564
Accumulated depreciation and amortization	(14,598)	(15,813)
Total property and equipment, net	4,586	4,751
Marine seismic service equipment
Property and equipment:
Property and equipment	4,533	5,969
Land and buildings
Property and equipment:
Property and equipment	4,384	4,354
Furniture and fixtures
Property and equipment:
Property and equipment	9,776	9,750
Autos and trucks
Property and equipment:
Property and equipment	$ 491	$ 491

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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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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