Accrued Expenses and Other Current Liabilities - Additional Information (Detail) $ in Thousands		12 Months Ended
	Nov. 13, 2014 USD ($) ft² Term	Apr. 30, 2015 USD ($)	Dec. 04, 2014 USD ($)	Apr. 30, 2014 USD ($)	Feb. 28, 2012 USD ($)	Oct. 31, 2009 USD ($)
Accrued Expenses and Other Current Liabilities [Line Items]
Leasehold improvement incentives received		$ 0			$ 600	$ 2,900
Lease expiration date		Dec. 31, 2015
Office space | ft²	137,615
Lease commencement date	Jan. 01, 2016
Lease termination period	10 years 6 months
Number of successive periods of five years terms | Term	2
Lease extension period	5 years
Expected lease payments for fiscal year ended April 30, 2016	$ 300
Expected lease payments for fiscal year ended April 30, 2017	3,800	$ 6,310
Expected lease payments for fiscal year ended April 30, 2018	3,800	6,081
Expected lease payments for fiscal year ended April 30, 2019	3,900	4,789
Expected lease payments for fiscal year ended April 30, 2020	4,000	4,658
Expected lease payments for fiscal years ended April 30th thereafter	25,900	25,940
Revolving Credit Facility | Credit Facility
Accrued Expenses and Other Current Liabilities [Line Items]
Letter of credit drawn	$ 8,000		$ 8,000
Accrued Liabilities
Accrued Expenses and Other Current Liabilities [Line Items]
Leasehold improvement incentives received		800		$ 1,200
Other Long Term Liabilities
Accrued Expenses and Other Current Liabilities [Line Items]
Leasehold improvement incentives received		$ 300		$ 1,200