Business Segments and Major Customer Information - Sales to countries outside the United States (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Segment Reporting Information [Line Items]
Net sales	$ 348,359	$ 382,530	$ 406,668
All foreign [Member]
Segment Reporting Information [Line Items]
Net sales	45,714	42,132	48,329
Canada
Segment Reporting Information [Line Items]
Net sales	13,025	12,121	12,492
Europe
Segment Reporting Information [Line Items]
Net sales	15,867	14,681	15,786
Latin America
Segment Reporting Information [Line Items]
Net sales	6,709	8,261	5,950
Asia
Segment Reporting Information [Line Items]
Net sales	5,168	3,387	7,240
Other foreign sales
Segment Reporting Information [Line Items]
Net sales	4,945	3,682	6,861
United States
Segment Reporting Information [Line Items]
Net sales	$ 302,645	$ 340,398	$ 358,339