Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Property, Plant and Equipment [Line Items]
Cost of property and equipment	$ 20,564	$ 22,470
Less accumulated depreciation	(15,813)	(17,051)
Net book value of property and equipment	4,751	5,419
Marine seismic service equipment
Property, Plant and Equipment [Line Items]
Cost of property and equipment	5,969	8,341
Land and buildings
Property, Plant and Equipment [Line Items]
Cost of property and equipment	4,354	4,274
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Cost of property and equipment	9,750	9,364
Autos and trucks
Property, Plant and Equipment [Line Items]
Cost of property and equipment	$ 491	$ 491