Changes in Accrued Special Charges (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Oct. 31, 2012		Oct. 31, 2011	Oct. 31, 2012		Oct. 31, 2011
Restructuring Cost and Reserve [Line Items]
Employee severance and related costs	$ 612		$ 1,227	$ 2,629		$ 3,581
Restructuring Reserve [Roll Forward]
Accrued special charges beginning balance				6,479
Charges				3,800
Payments				(5,524)
Accrued special charges ending balance	4,755	[1]		4,755	[1]
Other costs	534		(63)	1,171		3,807
Other Restructuring Costs	1,146		1,164	3,800		7,388
Employee severance and related costs
Restructuring Reserve [Roll Forward]
Accrued special charges beginning balance				3,668
Charges				2,629
Payments				(4,700)
Accrued special charges ending balance	1,597	[1]		1,597	[1]
Other costs
Restructuring Reserve [Roll Forward]
Accrued special charges beginning balance				2,811
Charges				1,171
Payments				(824)
Accrued special charges ending balance	$ 3,158	[1]		$ 3,158	[1]

[1] Of the $4,755 total accrued special charges as of October 31, 2012, $2,299 represented the long-term portion, which primarily included accrued lease termination fees and other facility costs, net of sublease income and other long-term costs. The remaining balance of $2,456 represented the short-term portion of accrued special charges.