Quarterly report pursuant to Section 13 or 15(d)

Net Loss Per Share - Exercise Prices of Common Shares above Market Price of Common Stock (Detail)

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Net Loss Per Share - Exercise Prices of Common Shares above Market Price of Common Stock (Detail) (Stock Options [Member])
In Thousands, unless otherwise specified
 3 Months Ended 6 Months Ended
Jul. 31, 2013
Jul. 31, 2012
Jul. 31, 2013
Jul. 31, 2012
Stock Options [Member]
        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Shares issuable upon the exercise of stock options that are anti-dilutive 691 1,225 634 670