Changes in Accrued Special Charges (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Oct. 31, 2013		Oct. 31, 2012	Oct. 31, 2013		Oct. 31, 2012
Accrued special charges [Roll Forward]
Accrued special charges beginning balance				$ 5,541
Special charges	4,688		1,975	12,570		6,406
Adjustments (payments)				(9,746)
Accrued special charges ending balance	8,365	[1]		8,365	[1]
Employee severance and related costs
Restructuring Cost and Reserve [Line Items]
Employee severance and related costs	1,133		612	3,843		2,629
Accrued special charges [Roll Forward]
Accrued special charges beginning balance				2,028
Adjustments (payments)				(4,641)
Accrued special charges ending balance	1,230	[1]		1,230	[1]
Litigation costs
Restructuring Cost and Reserve [Line Items]
Litigation costs	3,046		829	8,217		2,606
Accrued special charges [Roll Forward]
Accrued special charges beginning balance				624
Adjustments (payments)				(4,485)
Accrued special charges ending balance	4,356	[1]		4,356	[1]
Other costs
Restructuring Cost and Reserve [Line Items]
Other costs	509		534	510		1,171
Accrued special charges [Roll Forward]
Accrued special charges beginning balance				2,889
Adjustments (payments)				(620)
Accrued special charges ending balance	$ 2,779	[1]		$ 2,779	[1]

[1] Of the $8,365 total accrued special charges as of October 31, 2013, $660 represents the long-term portion, which primarily includes accrued lease termination fees and other facility costs, net of sublease income and other long-term costs. The remaining balance of $7,705 represents the short-term portion of accrued special charges.