Change in Allowance for Doubtful Accounts (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Oct. 31, 2013		Oct. 31, 2012
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning balance	$ 5,331		$ 4,432
Charged to expense	(331)		285
Deductions	(93)	[1]	(146)	[1]
Ending balance	$ 4,907		$ 4,571

[1] Specific account write-offs and foreign exchange.