Business Segments and Major Customer Information (Sales to Countries Outside the United States) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 258,229	$ 378,153	$ 394,677
All foreign [Member]
Segment Reporting Information [Line Items]
Net sales	27,849	36,835	45,893
Canada [Member]
Segment Reporting Information [Line Items]
Net sales	11,789	14,432	16,141
Europe [Member]
Segment Reporting Information [Line Items]
Net sales	10,526	8,243	4,131
Latin America [Member]
Segment Reporting Information [Line Items]
Net sales	2,676	9,921	22,124
Other foreign sales [Member]
Segment Reporting Information [Line Items]
Net sales	2,858	4,239	3,497
United States [Member]
Segment Reporting Information [Line Items]
Net sales	$ 230,380	$ 341,318	$ 348,784