Change in Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2015	Oct. 31, 2014
Allowance for doubtful accounts receivable, beginning balance	$ 4,217
Allowance for doubtful accounts receivable, ending balance	3,653
Allowance for Doubtful Accounts [Member]
Allowance for doubtful accounts receivable, beginning balance	4,217	$ 5,469
Valuation Allowances and Reserves, Period Increase (Decrease)	(522)	(1,865)
Valuation Allowances and Reserves, Adjustments	(42)	(252)
Allowance for doubtful accounts receivable, ending balance	$ 3,653	3,352
Allowance for doubtful accounts adjustment
Valuation Allowances and Reserves, Period Increase (Decrease)		$ (1,691)