Quarterly report pursuant to Section 13 or 15(d)

Segment Information, Significant Customers and Geographic Information - Additional Information (Detail)

v3.7.0.1
Segment Information, Significant Customers and Geographic Information - Additional Information (Detail)
3 Months Ended 6 Months Ended
Jul. 31, 2017
Jul. 31, 2016
Jul. 31, 2017
Segment
Customer
Jul. 31, 2016
Segment Reporting Information [Line Items]        
Number of reportable segment | Segment     1  
Total Revenues [Member]        
Segment Reporting Information [Line Items]        
Number of customers accounted | Customer     1  
Total Revenues [Member] | Customer Concentration Risk [Member]        
Segment Reporting Information [Line Items]        
Concentration risk percentage 10.00% 10.00% 10.00% 10.00%