Segment Information, Significant Customers and Geographic Information - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Segment Reporting Information [Line Items]
Total revenues	$ 115,435	$ 146,319	$ 157,188
United States Revenue [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 59,819	$ 66,903	$ 85,256
Customer Concentration Risk [Member] | United States Revenue [Member] | Total Revenue [Member]
Segment Reporting Information [Line Items]
% of total revenue	51.80%	45.70%	54.20%