The Company and its Significant Accounting Policies (Details) (USD $)	3 Months Ended			12 Months Ended
	Oct. 31, 2009	Jul. 31, 2007	Apr. 30, 2007	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
The Company and its Significant Accounting Policies (Textuals) [Abstract]
Excess warrant expense	$ 715,000
Stock Based Compensation Expenses	135,000	87,000	48,000	63,750,000	36,081,000	24,579,000
Maturity Period of Cash Equivalents				90 days or less
Maturity Period of Short Term Investments				90 days or more
Provision for doubtful accounts				17,000	265,000	138,000
Inventory Write-downs				2,647,000	2,949,000	3,397,000
Estimated useful lives of property, plant and equipments				2 to six years
Estimated economic lives of intangible assets, minimum				1
Estimated economic lives of intangible assets, maximum				7
Inventory Held By Resellers for Sale to End Customers				2,000,000	3,700,000
Service contract term, minimum				1 year
Service contract term, maximum				5 years
Term for professional service arrangements				90 days or less
Payment term range minimum				30 days
Payment term range maximum				60 days
Discrete tax benefits attributed to valuation allowances and net deferred tax assets				72,800,000
Valuation allowance				200,000
Unrecognized tax benefits				$ 10,900,000