Segment Reporting - Financial Information by Business Segment (Revenues) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2018	Oct. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 14,651	$ 8,644	$ 30,614	$ 37,913
Operating income (loss)	(349)	(4,793)	(10,497)	(12,054)
Income (loss) before taxes	(5,440)	(4,695)	(15,412)	(12,138)
Operating Segments | Marine Technology Products
Segment Reporting Information [Line Items]
Revenues	9,305	5,992	19,025	22,565
Operating income (loss)	876	(74)	(2,515)	1,160
Income (loss) before taxes	881	4	(2,441)	999
Operating Segments | Equipment Leasing
Segment Reporting Information [Line Items]
Revenues	5,386	2,730	11,906	15,546
Operating income (loss)	(347)	(3,927)	(5,369)	(10,571)
Income (loss) before taxes	(5,443)	(3,933)	(10,359)	(10,494)
Corporate expenses
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operating income (loss)	(864)	(792)	(2,599)	(2,643)
Income (loss) before taxes	(864)	(792)	(2,599)	(2,643)
Eliminations
Segment Reporting Information [Line Items]
Revenues	(40)	(78)	(317)	(198)
Operating income (loss)	(14)	0	(14)	0
Income (loss) before taxes	$ (14)	$ 26	$ (13)	$ 0