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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)

v3.7.0.1
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, 2017
Jul. 31, 2016
Jul. 31, 2017
Jul. 31, 2016
Segment Reporting Information [Line Items]        
Total revenues $ 17,225 $ 18,452 $ 33,892 $ 40,022
United States Revenue [Member]        
Segment Reporting Information [Line Items]        
Total revenues $ 7,047 $ 6,689 $ 14,075 $ 15,135
Total Revenues [Member] | Customer Concentration Risk [Member]        
Segment Reporting Information [Line Items]        
% of total revenues 10.00% 10.00% 10.00% 10.00%
Total Revenues [Member] | Customer Concentration Risk [Member] | United States Revenue [Member]        
Segment Reporting Information [Line Items]        
% of total revenues 40.90% 36.30% 41.50% 37.80%