Income Taxes - Income Tax Expense (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Current tax expense (benefit):
Federal	$ 907	$ 941	$ 247
State and local	168	184	63
Foreign	917	791	838
Total current tax expense	1,992	1,916	1,148
Deferred tax expense (benefit):
Federal	27	(346)	(338)
State and local	26	(24)	(12)
Foreign	(62)	(6)	(59)
Total deferred tax expense (benefit)	(9)	(376)	(409)
Net income tax expense	$ 1,983	$ 1,540	$ 739