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)

v3.19.2
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, 2019
Jul. 31, 2018
Jul. 31, 2019
Jul. 31, 2018
Segment Reporting Information [Line Items]        
Total revenues $ 18,812 $ 11,901 $ 27,297 $ 26,836
United States Revenue [Member]        
Segment Reporting Information [Line Items]        
Total revenues $ 9,666 $ 5,102 $ 13,064 $ 10,889
Total Revenues [Member] | Customer Concentration Risk [Member] | United States Revenue [Member]        
Segment Reporting Information [Line Items]        
% of total revenue 51.00% 43.00% 48.00% 41.00%