Summary of Significant Accounting Policies - Estimated Useful Lives Of The Assets (Detail)	12 Months Ended
	Jul. 31, 2012
Computer And Telecommunications Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Computer and telecommunications equipment	2 years
Computer And Telecommunications Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Computer and telecommunications equipment	3 years
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Computer and telecommunications equipment	3 years
Furniture And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Computer and telecommunications equipment	5 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Leasehold improvements	Shorter of lease term or useful life of asset