Business Segments and Major Customer Information - Sales to countries outside the United States (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 378,153	$ 394,677	$ 406,175
All foreign [Member]
Segment Reporting Information [Line Items]
Net sales	36,835	45,893	49,254
Canada [Member]
Segment Reporting Information [Line Items]
Net sales	14,432	16,141	20,640
South America [Member]
Segment Reporting Information [Line Items]
Net sales	9,884	22,090	14,984
Other foreign sales [Member]
Segment Reporting Information [Line Items]
Net sales	12,519	7,662	13,630
United States [Member]
Segment Reporting Information [Line Items]
Net sales	$ 341,318	$ 348,784	$ 356,921