Seismic Equipment Lease Pool and Property and Equipment (Details 1) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	$ 119,608	$ 120,377	$ 79,095
United States [Member]
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	40,908	65,922
Canada [Member]
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	22,639	23,856
Latin America [Member]
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	23,109	21,963
Australia [Member]
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	7,973	2,553
Russia [Member]
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	3,708	2,323
Singapore [Member]
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	9,433	3,352
United Kingdom [Member]
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	329	232
Europe [Member]
Location of seismic equipment lease pool and property and equipment
Seismic equipment lease pool and property and equipment, net	$ 11,509	$ 176