Segment Reporting - Financial Information by Business Segment (Revenues) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 8,898	$ 8,350	$ 18,755	$ 15,963
Operating loss	(3,062)	(4,576)	(5,518)	(10,148)
Loss before taxes	(3,088)	(4,504)	(5,448)	(9,972)
Operating Segments | Marine Technology Products
Segment Reporting Information [Line Items]
Revenues	6,745	6,012	12,727	9,720
Operating loss	(718)	(1,016)	(1,879)	(3,391)
Loss before taxes	(621)	(973)	(1,782)	(3,322)
Operating Segments | Equipment Leasing
Segment Reporting Information [Line Items]
Revenues	2,175	2,473	6,110	6,520
Operating loss	(1,551)	(2,655)	(1,940)	(5,022)
Loss before taxes	(1,674)	(2,626)	(1,967)	(4,916)
Corporate expenses
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operating loss	(793)	(905)	(1,699)	(1,735)
Loss before taxes	(793)	(905)	(1,699)	(1,735)
Eliminations
Segment Reporting Information [Line Items]
Revenues	(22)	(135)	(82)	(277)
Operating loss	0	0	0	0
Loss before taxes	$ 0	$ 0	$ 0	$ 1