Segment Reporting - Financial Information by Business Segment (Assets) (Detail) - USD ($) $ in Thousands	Jul. 31, 2018	Jan. 31, 2018
Segment Reporting Information [Line Items]
Total Assets	$ 68,114	$ 73,679
Operating Segments | Marine Technology Products
Segment Reporting Information [Line Items]
Total Assets	43,228	35,879
Operating Segments | Equipment Leasing
Segment Reporting Information [Line Items]
Total Assets	24,918	37,850
Eliminations
Segment Reporting Information [Line Items]
Total Assets	$ (32)	$ (50)