Goodwill and Intangible Assets (Details 2) (USD $) In Thousands	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Summary of amortization expense of intangible assets
Amortization expense of intangible assets	$ 7,824	$ 4,804	$ 4,937
Cost of product revenues [Member]
Summary of amortization expense of intangible assets
Amortization expense of intangible assets	5,852	3,082	3,082
Cost of professional service and support revenues [Member]
Summary of amortization expense of intangible assets
Amortization expense of intangible assets	540	540	540
Sales and marketing [Member]
Summary of amortization expense of intangible assets
Amortization expense of intangible assets	$ 1,432	$ 1,182	$ 1,315