Balance Sheet (Details 2) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013	Jan. 31, 2013
Seismic equipment lease pool and property and equipment:
Seismic equipment lease pool and property and equipment, gross	$ 243,410	$ 251,408
Accumulated depreciation and amortization	(137,536)	(131,800)
Total seismic equipment lease pool and property and equipment, net	105,874	119,608
Seismic equipment lease pool [Member]
Seismic equipment lease pool and property and equipment:
Seismic equipment lease pool	233,376	241,395
Land and buildings [Member]
Seismic equipment lease pool and property and equipment:
Seismic equipment lease pool and property and equipment, gross	366	366
Furniture and fixtures [Member]
Seismic equipment lease pool and property and equipment:
Seismic equipment lease pool and property and equipment, gross	8,861	8,899
Autos and trucks [Member]
Seismic equipment lease pool and property and equipment:
Seismic equipment lease pool and property and equipment, gross	$ 807	$ 748