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Supplemental Statements of Cash Flows Information - Supplemental Disclosures of Cash Flows Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Jan. 31, 2019
Jan. 31, 2018
Jan. 31, 2017
Supplemental Cash Flow Elements [Abstract]      
Interest paid $ 8 $ 86 $ 673
Income taxes paid, net 622 494 409
Seismic equipment purchases included in accounts payable at year-end $ 0 $ 53 $ 130