Segment Information, Significant Customers and Geographic Information - Schedule of Revenue by Major Customers by Reporting Segments (Detail) (Customer Concentration Risk [Member], Total Revenue [Member])	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Customera [Member]
Revenue, Major Customer [Line Items]
% of total revenues	17.00%	15.00%	18.00%
Customer B [Member]
Revenue, Major Customer [Line Items]
% of total revenues	15.00%	24.00%	21.00%
Customer C [Member]
Revenue, Major Customer [Line Items]
% of total revenues		10.00%