Income Taxes - Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Income Tax Disclosure [Abstract]
Federal									$ (38)
State									182	$ 294	$ 931
International									951	567	518
Total									1,095	861	1,449
Federal									(12,491)	(13,930)	(11,190)
State									(2,308)	(2,091)	9
International									44	203	(90)
Total									(14,755)	(15,818)	(11,271)
Change in valuation allowance									13,714	14,457	8,650
Provision for (benefit from) income taxes	$ (540)	$ 324	$ 258	$ 12	$ (418)	$ 179	$ 130	$ (391)	$ 54	$ (500)	$ (1,172)