Balance Sheet - Schedule of Seismic Equipment Lease Pool and Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Jan. 31, 2014
Seismic equipment lease pool and property and equipment:
Cost of seismic equipment lease pool and property and equipment	$ 271,102	$ 271,684
Accumulated depreciation and amortization	(146,806)	(142,111)
Total seismic equipment lease pool and property and equipment, net	124,296	129,573
Seismic Equipment Lease Pool [Member]
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	260,827	261,644
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	9,120	8,904
Autos and Trucks [Member]
Seismic equipment lease pool and property and equipment:
Cost of property and equipment	$ 789	$ 770