Acquisitions (Details) (USD $)	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009	Oct. 31, 2008
Business Acquisition [Line Items]
Acquisition-related restructuring liabilities				$ (2,713,000)
In-process research and development	0	0	6,200,000
Payment of contingent consideration related to business acquisition	24,000	0	0
Business acquisition, contingent consideration at fair value, current	726,000	1,350,000
Customer relationships [Member] | Acquisition Of Radyne Corporation [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets, useful life			10
Technologies [Member] | Acquisition Of Radyne Corporation [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets, useful life, minimum			7
Finite-lived intangible assets, useful life, maximum			15
Trademarks and other [Member] | Acquisition Of Radyne Corporation [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets, useful life, minimum			2
Finite-lived intangible assets, useful life, maximum			20
Acquisition of Stampede Technologies, Inc. [Member]
Business Acquisition [Line Items]
Name of acquired entity	Stampede Technologies, Inc.
Effective date of acquisition	October 2010
Aggregate purchase price	5,303,000
Purchase price paid in cash	1,524,000
Payment of contingent consideration related to business acquisition	24,000
Business acquisition, contingent consideration at fair value, noncurrent	3,444,000
Business acquisition, contingent consideration at fair value, current	726,000
Business acquisition, contingent consideration at fair value, accretion expense	391,000
Useful life of technologies acquired, in years	5
Fair value of contingent consideration arrangement	3,803,000
Acquisition Of Radyne Corporation [Member]
Business Acquisition [Line Items]
Name of acquired entity			Radyne Corporation
Effective date of acquisition			August 1, 2008
Fair value of Radyne net tangible assets acquired			66,296,000
Acquisition-related restructuring liabilities			(2,713,000)
Inventory step-up			1,520,000
Deferred tax assets, net			441,000
Fair value of net tangible assets acquired			65,544,000
In-process research and development			6,200,000
Customer relationships			29,600,000
Technologies			19,900,000
Trademarks and other			5,700,000
Goodwill			124,873,000
Deferred tax liabilities			(20,424,000)
Fair value of net intangible assets acquired			165,849,000
Aggregate purchase price			$ 231,393,000
Number of acquired in-process R&D projects completed			4