Segment Reporting - Financial Information by Business Segment (Revenues) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 12,328	$ 14,651	$ 8,350	$ 7,613	$ 10,363	$ 8,644	$ 10,836	$ 18,433	$ 42,942	$ 48,276	$ 40,999
Interest expense, net									72	47	(643)
Operating (loss) income									(13,020)	(19,708)	(31,290)
Capital expenditures									2,531	1,316	919
Depreciation and amortization expense									11,814	16,637	28,275
Corporate expenses
Segment Reporting Information [Line Items]
Revenues									0	0	0
Interest expense, net									0	0	0
Operating (loss) income									(3,375)	(3,211)	(3,001)
Capital expenditures									0	0	0
Depreciation and amortization expense									0	0	0
Marine Technology Products | Operating segments
Segment Reporting Information [Line Items]
Revenues									25,768	27,572	25,100
Interest expense, net									0	(18)	(178)
Operating (loss) income									(3,780)	(2,572)	(508)
Capital expenditures									583	268	263
Depreciation and amortization expense									2,418	1,991	2,054
Equipment Leasing | Operating segments
Segment Reporting Information [Line Items]
Revenues									17,383	20,919	15,941
Interest expense, net									72	65	(465)
Operating (loss) income									(5,872)	(13,930)	(27,782)
Capital expenditures									1,948	1,048	656
Depreciation and amortization expense									$ 9,402	$ 14,652	$ 26,221