Annual report pursuant to Section 13 and 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
 12 Months Ended
Jan. 31, 2018
Jan. 31, 2017
Jan. 31, 2016
Segment Reporting Information [Line Items]      
Total revenues $ 80,267 $ 83,795 $ 106,992
United States Revenue [Member]      
Segment Reporting Information [Line Items]      
Total revenues $ 27,876 $ 30,094 $ 46,978
Total Revenues [Member] | Customer Concentration Risk [Member]      
Segment Reporting Information [Line Items]      
% of total revenue 10.00% 10.00% 10.00%
Total Revenues [Member] | Customer Concentration Risk [Member] | United States Revenue [Member]      
Segment Reporting Information [Line Items]      
% of total revenue 34.70% 35.90% 43.90%