Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 31, 2016 Customer	Oct. 31, 2015 Customer	Oct. 31, 2016 USD ($) Customer	Oct. 31, 2015 Customer	Apr. 30, 2016 Customer
Accounting Policies [Abstract]
Number of clients that accounted for more than 10% of account receivables	0		0		0
Number of clients that accounted for more than 10% of revenue	0	0	0	0
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax | $			$ 0.6
Minimum [Member] | Software as a Service (“SaaS”)
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Service agreement period			1 year
Maximum [Member] | Software as a Service (“SaaS”)
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Service agreement period			3 years