Changes in Accrued Special Charges (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jul. 31, 2012		Jul. 31, 2011	Jul. 31, 2012		Jul. 31, 2011
Restructuring Cost and Reserve [Line Items]
Employee severance and related costs	$ 1,029		$ 1,207	$ 2,017		$ 2,354
Restructuring Reserve [Roll Forward]
Accrued special charges beginning balance				6,479
Charges				2,654
Payments				(4,089)
Accrued special charges ending balance	5,044	[1]		5,044	[1]
Other costs	478		470	637		3,870
Other Restructuring Costs	1,507		1,677	2,654		6,224
Employee severance and related costs
Restructuring Reserve [Roll Forward]
Accrued special charges beginning balance				3,668
Charges				2,017
Payments				(3,769)
Accrued special charges ending balance	1,916	[1]		1,916	[1]
Other costs
Restructuring Reserve [Roll Forward]
Accrued special charges beginning balance				2,811
Charges				637
Payments				(320)
Accrued special charges ending balance	$ 3,128	[1]		$ 3,128	[1]

[1] Of the $5,044 total accrued special charges as of July 31, 2012, $2,431 represented the long-term portion of accrued lease termination fees and other facility costs, net of sublease income and other long-term costs. The remaining balance of $2,613 represented the short-term portion of accrued special charges.