Segment Reporting - Financial Information by Business Segment (Revenues) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 13,257	$ 10,663	$ 8,898	$ 9,857	$ 12,328	$ 14,651	$ 8,350	$ 7,613	$ 42,675	$ 42,942	$ 48,276
Interest expense, net									(46)	72	47
Operating loss									(10,375)	(13,020)	(19,708)
Capital expenditures									3,991	2,531	1,316
Depreciation and amortization expense									7,768	11,814	16,637
Corporate expenses
Segment Reporting Information [Line Items]
Revenues									0	0	0
Interest expense, net									0	0	0
Operating loss									(3,471)	(3,375)	(3,211)
Capital expenditures									0	0	0
Depreciation and amortization expense									0	0	0
Marine Technology Products | Operating segments
Segment Reporting Information [Line Items]
Revenues									29,572	25,768	27,572
Interest expense, net									1	0	(18)
Operating loss									(2,259)	(3,780)	(2,572)
Capital expenditures									894	583	268
Depreciation and amortization expense									2,649	2,418	1,991
Equipment Leasing | Operating segments
Segment Reporting Information [Line Items]
Revenues									13,213	17,383	20,919
Interest expense, net									(47)	72	65
Operating loss									(4,667)	(5,872)	(13,930)
Capital expenditures									3,097	1,948	1,048
Depreciation and amortization expense									$ 5,141	$ 9,402	$ 14,652