Change in Allowance for Doubtful Accounts (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 30, 2012
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	$ 4,432
Charged to expense	153
Deductions	(48)	[1]
Ending Balance	$ 4,537

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