Nature of Business and Basis of Presentation - Reclassification Reflected in Current Statements of Operations and Comprehensive Income (Loss) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jul. 31, 2012	Jul. 31, 2012
Basis Of Presentation [Line Items]
Prior period reclassification adjustment
Cost of Revenue Product [Member]
Basis Of Presentation [Line Items]
Prior period reclassification adjustment	(58)	(112)
Cost of Revenue Service [Member]
Basis Of Presentation [Line Items]
Prior period reclassification adjustment	(248)	(487)
Research and Development Expenses [Member]
Basis Of Presentation [Line Items]
Prior period reclassification adjustment	(190)	(372)
Selling and Marketing Expenses [Member]
Basis Of Presentation [Line Items]
Prior period reclassification adjustment	(41)	(81)
General and Administrative Expenses [Member]
Basis Of Presentation [Line Items]
Prior period reclassification adjustment	$ 537	$ 1,052