Segment Reporting - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012	Jan. 31, 2013
Entity Wide Portfolio Carrying Amount, Major Customer [Line Items]
Percentage of revenue	87.00%	82.00%	84.00%	81.00%
Accounts receivable from major customers	$ 20.0		$ 20.0		$ 17.6
Wintech [Member]
Entity Wide Portfolio Carrying Amount, Major Customer [Line Items]
Threshold limit	10.00%	10.00%	10.00%	10.00%	10.00%
Chicony [Member]
Entity Wide Portfolio Carrying Amount, Major Customer [Line Items]
Threshold limit	10.00%	10.00%	10.00%	10.00%	10.00%