Net Loss Per Share - Anti-Dilutive Effect Due to Net Loss (Detail) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from calculation of diluted loss per share	681	534	707	507
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from calculation of diluted loss per share	192	53	213	50
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from calculation of diluted loss per share	489	481	494	457