Balance Sheet - Schedule of Seismic Equipment Lease Pool and Property and Equipment (Detail) - USD ($) $ in Thousands	Jul. 31, 2015	Jan. 31, 2015	Jan. 31, 2014
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	$ 254,279		$ 253,698
Accumulated depreciation and amortization	(167,737)		(153,611)
Total seismic equipment lease pool and property and equipment, net	86,542	$ 100,087	100,087
Seismic Equipment Lease Pool [Member]
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	243,744		243,211
Land and Buildings [Member]
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	366		366
Furniture and Fixtures [Member]
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	9,460		9,399
Autos and Trucks [Member]
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	$ 709		$ 722