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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 9 Months Ended
Oct. 31, 2016
Oct. 31, 2015
Oct. 31, 2016
Oct. 31, 2015
Segment Reporting Information [Line Items]        
Total revenues $ 19,961 $ 28,747 $ 59,983 $ 79,795
United States Revenue [Member]        
Segment Reporting Information [Line Items]        
Total revenues $ 6,905 $ 11,880 $ 22,040 $ 35,609
Total Revenue [Member] | Customer Concentration Risk [Member] | United States Revenue [Member]        
Segment Reporting Information [Line Items]        
% of total revenues 34.60% 41.30% 36.70% 44.60%