Quarterly report pursuant to Section 13 or 15(d)

Segment Information, Significant Customers and Geographic Information - Schedule of Revenue by Major Customers by Reporting Segments (Detail)

v3.8.0.1
Segment Information, Significant Customers and Geographic Information - Schedule of Revenue by Major Customers by Reporting Segments (Detail) - Customer Concentration Risk [Member] - Total Revenues [Member]
 3 Months Ended 9 Months Ended
Oct. 31, 2017
Oct. 31, 2016
Oct. 31, 2017
Oct. 31, 2016
Revenue, Major Customer [Line Items]        
% of total revenues 10.00% 10.00% 10.00% 10.00%
Customer A [Member]        
Revenue, Major Customer [Line Items]        
% of total revenues 53.00% 33.00% 38.00% 31.00%