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Segment Information, Significant Customers and Geographic Information - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area (Parenthetical) (Detail)

v3.5.0.2
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
3 Months Ended 6 Months Ended
Jul. 31, 2016
Jul. 31, 2015
Jul. 31, 2016
Jul. 31, 2015
Segment Reporting Information [Line Items]        
Total revenues $ 18,452 $ 27,871 $ 40,022 $ 51,048
United States Revenue [Member]        
Segment Reporting Information [Line Items]        
Total revenues $ 6,689 $ 11,794 $ 15,135 $ 23,729
Total Revenue [Member] | Customer Concentration Risk [Member] | United States Revenue [Member]        
Segment Reporting Information [Line Items]        
% of total revenues 36.30% 42.30% 37.80% 46.50%