Business Segments and Major Customer Information - Sales to countries outside the United States (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Segment Reporting Information [Line Items]
Net sales	$ 277,395	$ 258,229	$ 378,153
All foreign [Member]
Segment Reporting Information [Line Items]
Net sales	35,528	27,849	36,835
Canada [Member]
Segment Reporting Information [Line Items]
Net sales	13,969	11,789	14,432
Europe [Member]
Segment Reporting Information [Line Items]
Net sales	13,924	10,526	8,243
Latin America [Member]
Segment Reporting Information [Line Items]
Net sales	3,402	2,676	9,921
Other foreign sales [Member]
Segment Reporting Information [Line Items]
Net sales	4,233	2,858	4,239
United States [Member]
Segment Reporting Information [Line Items]
Net sales	$ 241,867	$ 230,380	$ 341,318