Change in Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Allowance for doubtful accounts receivable, beginning balance	$ 3,826
Allowance for doubtful accounts receivable, ending balance	4,089	$ 3,826
Allowance for doubtful accounts adjustment
Valuation Allowances and Reserves, Period Increase (Decrease)			$ (1,691)
Allowance for Doubtful Accounts [Member]
Allowance for doubtful accounts receivable, beginning balance	3,826	4,217	5,469
Valuation Allowances and Reserves, Period Increase (Decrease)	(58)	(349)	(988)
Valuation Allowances and Reserves, Adjustments	321	(42)	(264)
Allowance for doubtful accounts receivable, ending balance	$ 4,089	$ 3,826	$ 4,217