Quarterly report pursuant to Section 13 or 15(d)

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

v3.8.0.1
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
Apr. 30, 2018
Apr. 30, 2017
Segment Reporting Information [Line Items]    
Total revenues $ 14,935 $ 16,667
United States Revenue [Member]    
Segment Reporting Information [Line Items]    
Total revenues $ 5,787 $ 7,028
Total Revenues [Member] | Customer Concentration Risk [Member] | United States Revenue [Member]    
Segment Reporting Information [Line Items]    
% of total revenues 38.70% 42.20%