Segment Reporting - Financial Information by Business Segment (Assets) (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2015	Jan. 31, 2015
Segment Reporting Information [Line Items]
Total Assets	$ 178,317	$ 179,611
Operating Segments [Member] | Equipment Leasing [Member]
Segment Reporting Information [Line Items]
Total Assets	146,151	148,985
Operating Segments [Member] | Seamap [Member]
Segment Reporting Information [Line Items]
Total Assets	32,489	30,982
Eliminations [Member]
Segment Reporting Information [Line Items]
Total Assets	$ (323)	$ (356)