Long Lived Assets, Excluding Financial Instruments and Tax Assets, Classified by Controlling Countries over Ten Percent (Detail) - USD ($) $ in Thousands		Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Segment Reporting Information [Line Items]
Long-lived assets	[1]	$ 109,567	$ 95,436	$ 62,088
UNITED STATES
Segment Reporting Information [Line Items]
Long-lived assets	[2]	70,949	64,525	50,103
Other Countries
Segment Reporting Information [Line Items]
Long-lived assets		$ 38,618	$ 30,911	$ 11,985

[1] As of the end of the fiscal year.

[2] Includes Corporate long-lived assets