Acquired Intangible Assets, net - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization Of Intangible Assets Including Portion In Cost Of Revenue	$ 1.9	$ 1.9	$ 1.9

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration