Change in Allowance for Doubtful Accounts (Detail) (USD $) In Thousands	6 Months Ended
	Jul. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	$ 3,941
Charged (credited) to expense	(218)
Deductions	(153)	[1]
Ending Balance	$ 3,570

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