Supplemental Statements of Cash Flows Information - Supplemental Disclosures of Cash Flows Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Supplemental Cash Flow Elements [Abstract]
Interest paid	$ 342	$ 533	$ 704
Income taxes paid, net	215	9,177	7,536
Seismic equipment purchases included in accounts payable at year-end	7,707	4,268	9,900
Stock issued for accrued compensation		$ 516	$ 303