Segment Reporting - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Segment Reporting Disclosure [Line Items]
Percentage of revenue	80.00%	80.00%	91.00%
Accounts receivable with logistic provider and a direct ODM customer	$ 17.6	$ 7.8
Customer A [Member]
Segment Reporting Disclosure [Line Items]
Threshold limit	10.00%	10.00%	10.00%
Customer B [Member]
Segment Reporting Disclosure [Line Items]
Threshold limit	10.00%