Note 2 - Significant Accounting Policies - Long-Lived Assets (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Jan. 31, 2019
Property, plant and equipment	$ 77,816	$ 77,141
Less accumulated depreciation	49,187	46,743
Property, plant and equipment, net of accumulated depreciation	28,629	30,398
Land, Buildings and Improvements [Member]
Property, plant and equipment	22,328	22,327
Machinery and Equipment [Member]
Property, plant and equipment	47,409	47,168
Furniture and Fixtures [Member]
Property, plant and equipment	4,317	4,335
Transportation Equipment [Member]
Property, plant and equipment	$ 3,762	$ 3,311