Segment Reporting - Financial Information by Business Segment (Revenues) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 10,363	$ 8,644	$ 10,836	$ 18,433	$ 12,548	$ 8,057	$ 8,663	$ 11,731	$ 48,276	$ 40,999	$ 51,819
Interest expense, net									47	(643)	(725)
Operating (loss) income									(19,708)	(31,290)	(26,760)
Capital expenditures									1,317	283	2,509
Depreciation and amortization expense									16,637	28,275	32,111
Corporate expenses
Segment Reporting Information [Line Items]
Revenues									0	0	0
Interest expense, net									0	0	0
Operating (loss) income									(3,211)	(3,001)	(3,702)
Capital expenditures									0	0	0
Depreciation and amortization expense									0	0	0
Equipment Leasing | Operating Segments
Segment Reporting Information [Line Items]
Revenues									20,919	15,941	26,665
Interest expense, net									65	(465)	(486)
Operating (loss) income									(13,930)	(27,782)	(23,454)
Capital expenditures									1,049	20	2,283
Depreciation and amortization expense									14,652	26,221	30,370
Marine Technology Products | Operating Segments
Segment Reporting Information [Line Items]
Revenues									27,572	25,100	25,350
Interest expense, net									(18)	(178)	(239)
Operating (loss) income									(2,572)	(508)	279
Capital expenditures									268	263	226
Depreciation and amortization expense									$ 1,991	$ 2,054	$ 1,741