Balance Sheet (Details 2) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jan. 31, 2012
Seismic equipment lease pool and property and equipment:
Seismic equipment lease pool and property and equipment, gross	$ 239,494	$ 232,559
Accumulated depreciation and amortization	(120,995)	(112,182)
Total seismic equipment lease pool and property and equipment, net	118,499	120,377
Seismic equipment lease pool [Member]
Seismic equipment lease pool and property and equipment:
Seismic equipment lease pool and property and equipment, gross	229,901	223,493
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	8,547	8,020
Autos and Trucks [Member]
Seismic equipment lease pool and property and equipment:
Seismic equipment lease pool and property and equipment, gross	$ 680	$ 680

The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

+ References+ Details

Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References+ Details

- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References+ Details