Segment Reporting - Financial Information by Business Segment (Assets) (Detail) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Segment Reporting Information [Line Items]
Fixed assets, net	$ 14,155	$ 22,900	$ 43,838
Intangible assets, net	10,495	8,015	9,012
Goodwill	2,531	2,531	3,997
Total Assets	65,301	73,679	94,714
Marine Technology Products
Segment Reporting Information [Line Items]
Fixed assets, net	4,635	3,790	4,036
Intangible assets, net	10,417	8,015	9,012
Goodwill	2,531	2,531	3,997
Total Assets	44,832	35,879	37,294
Equipment Leasing
Segment Reporting Information [Line Items]
Fixed assets, net	9,534	19,161	39,926
Intangible assets, net	78	0	0
Goodwill	0	0	0
Total Assets	$ 20,469	$ 37,850	$ 57,544