Segment Reporting - Financial Information by Business Segment (Revenues) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 8,350	$ 10,836	$ 15,963	$ 29,269
Operating income (loss)	(4,576)	(4,972)	(10,148)	(7,261)
Income (loss) before taxes	(4,504)	(5,007)	(9,972)	(7,443)
Operating Segments | Marine Technology Products
Segment Reporting Information [Line Items]
Revenues	6,012	9,662	9,720	16,573
Operating income (loss)	(1,016)	850	(3,391)	1,234
Income (loss) before taxes	(973)	882	(3,322)	995
Operating Segments | Equipment Leasing
Segment Reporting Information [Line Items]
Revenues	2,473	1,271	6,520	12,816
Operating income (loss)	(2,655)	(4,988)	(5,022)	(6,644)
Income (loss) before taxes	(2,626)	(5,041)	(4,916)	(6,561)
Corporate expenses
Segment Reporting Information [Line Items]
Revenues			0	0
Operating income (loss)	(905)	(834)	(1,735)	(1,851)
Income (loss) before taxes	(905)	(834)	(1,735)	(1,851)
Eliminations
Segment Reporting Information [Line Items]
Revenues	(135)	(97)	(277)	(120)
Operating income (loss)	0	0	0	0
Income (loss) before taxes	$ 0	$ (14)	$ 1	$ (26)