Estimated Useful Lives of Property Plant and Equipment (Detail)	12 Months Ended
	Apr. 30, 2013
Computer Equipment
Property Plant And Equipment Estimated Useful Lifes [Line Items]
Estimated useful life	3 years
Furniture and Fixtures
Property Plant And Equipment Estimated Useful Lifes [Line Items]
Estimated useful life	5 years
Office Equipment
Property Plant And Equipment Estimated Useful Lifes [Line Items]
Estimated useful life	5 years
Software
Property Plant And Equipment Estimated Useful Lifes [Line Items]
Estimated useful life	3 years
Leasehold Improvements
Property Plant And Equipment Estimated Useful Lifes [Line Items]
Estimated useful life	Shorter of estimated useful life or the lease term