Goodwill and Intangible Assets (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010
Company's total purchased intangible assets
Intangible assets, Estimated Useful Lives, Minimum, years	1
Intangible assets, Estimated Useful Lives, Maximum, years	7
Intangible assets, Gross Value	$ 40,841	$ 21,441
Intangible assets, Accumulated Amortization	(19,978)	(12,154)
Intangible assets, Net Value	20,863	9,287
Existing Technology [Member]
Company's total purchased intangible assets
Intangible assets, Estimated Useful Lives, years		4
Intangible assets, Estimated Useful Lives, Minimum, years	4
Intangible assets, Estimated Useful Lives, Maximum, years	5
Intangible assets, Gross Value	22,383	9,283
Intangible assets, Accumulated Amortization	(10,595)	(5,914)
Intangible assets, Net Value	11,788	3,369
In Process Research And Development [Member]
Company's total purchased intangible assets
Intangible assets, Gross Value	1,020
Intangible assets, Accumulated Amortization	0
Intangible assets, Net Value	1,020
Patents/Core Technology [Member]
Company's total purchased intangible assets
Intangible assets, Estimated Useful Lives, years		4
Intangible assets, Estimated Useful Lives, Minimum, years	4
Intangible assets, Estimated Useful Lives, Maximum, years	6
Intangible assets, Gross Value	6,026	3,046
Intangible assets, Accumulated Amortization	(3,110)	(1,940)
Intangible assets, Net Value	2,916	1,106
Customer Contracts [Member]
Company's total purchased intangible assets
Intangible assets, Estimated Useful Lives, Minimum, years	6	6
Intangible assets, Estimated Useful Lives, Maximum, years	7	7
Intangible assets, Gross Value	6,933	5,083
Intangible assets, Accumulated Amortization	(3,137)	(2,020)
Intangible assets, Net Value	3,796	3,063
Support Agreements [Member]
Company's total purchased intangible assets
Intangible assets, Estimated Useful Lives, Minimum, years	5	5
Intangible assets, Estimated Useful Lives, Maximum, years	6	6
Intangible assets, Gross Value	2,917	2,717
Intangible assets, Accumulated Amortization	(1,849)	(1,284)
Intangible assets, Net Value	1,068	1,433
Tradenames/Trademarks [Member]
Company's total purchased intangible assets
Intangible assets, Estimated Useful Lives, years		5
Intangible assets, Estimated Useful Lives, Minimum, years	1
Intangible assets, Estimated Useful Lives, Maximum, years	5
Intangible assets, Gross Value	750	600
Intangible assets, Accumulated Amortization	(529)	(284)
Intangible assets, Net Value	221	316
Non-Compete Agreements [Member]
Company's total purchased intangible assets
Intangible assets, Estimated Useful Lives, years	2	2
Intangible assets, Gross Value	812	712
Intangible assets, Accumulated Amortization	(758)	(712)
Intangible assets, Net Value	$ 54	$ 0