Change in Allowance for Doubtful Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Allowance for doubtful accounts receivable, ending balance	$ 4,217	$ 5,469
Allowance for Doubtful Accounts [Member]
Allowance for doubtful accounts receivable, beginning balance	5,469	5,331	4,432
Valuation Allowances and Reserves, Charged to Cost and Expense	(988)	517	1,147
Net Deductions Recoveries	(264)	(379)	(248)
Allowance for doubtful accounts receivable, ending balance	$ 4,217	$ 5,469	$ 5,331