Balance Sheet - Schedule of Seismic Equipment Lease Pool and Property and Equipment (Detail) - USD ($) $ in Thousands	Apr. 30, 2018	Jan. 31, 2018
Seismic equipment lease pool and property and equipment:
Cost of seismic equipment lease pool and property and equipment	$ 185,300	$ 188,598
Accumulated depreciation and amortization	(164,254)	(165,698)
Total seismic equipment lease pool and property and equipment, net	21,046	22,900
Seismic equipment lease pool
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	170,654	174,274
Land and buildings
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	3,381	3,380
Furniture and fixtures
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	10,504	10,222
Autos and trucks
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	$ 761	$ 722