Summary of Business and Significant Accounting Policies - Additional Information (Detail) - Customer	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
Summary Of Business And Accounting Policies [Line Items]
Period of amortization	3 years
Customer concentration risk [Member] | Revenues [Member]
Summary Of Business And Accounting Policies [Line Items]
Number of customers	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