Segment Reporting - Financial Information by Business Segment (Assets) (Detail) - USD ($) $ in Thousands	Apr. 30, 2018	Jan. 31, 2018
Segment Reporting Information [Line Items]
Total Assets	$ 72,724	$ 73,679
Operating Segments | Marine Technology Products
Segment Reporting Information [Line Items]
Total Assets	35,872	35,879
Operating Segments | Equipment Leasing
Segment Reporting Information [Line Items]
Total Assets	36,893	37,850
Eliminations
Segment Reporting Information [Line Items]
Total Assets	$ (41)	$ (50)