Summary of Business and Significant Accounting Policies - Additional Information (Detail) - Customer	1 Months Ended	3 Months Ended		6 Months Ended
	May 31, 2016	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Summary Of Business And Accounting Policies [Line Items]
Number of customers	38
Customer concentration risk [Member] | Revenues [Member]
Summary Of Business And Accounting Policies [Line Items]
Number of customers		0	0	0	0
Minimum [Member]
Summary Of Business And Accounting Policies [Line Items]
Customer payment period				30 days
Maximum [Member]
Summary Of Business And Accounting Policies [Line Items]
Customer payment period				60 days