Special Charges - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jul. 31, 2012		Jul. 31, 2011	Jan. 31, 2012
Disclosure Special Charges Additional Information [Abstract]
Percentage of termination benefit paid during the period	52.00%
Costs related to advisory fees			$ 3,838
Accrued special charges ending balance	5,044	[1]		6,479
Long-term portion of accrued lease termination fees and other facility costs, net of sublease income	2,431
Short-term portion of accrued special charges	$ 2,613

[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.