Goodwill (Details) (USD $)	12 Months Ended							12 Months Ended
	Jul. 31, 2014 operating_segment	Jul. 31, 2013 operating_segment	Jul. 31, 2012 operating_segment	Jul. 31, 2014 Telecommunications Transmission Segment	Jul. 31, 2013 Telecommunications Transmission Segment	Jul. 31, 2014 RF Microwave Amplifiers Segment	Jul. 31, 2013 RF Microwave Amplifiers Segment	Jul. 31, 2010 Mobile Data Communications Segment	Jul. 31, 2014 Mobile Data Communications Segment	Jul. 31, 2013 Mobile Data Communications Segment
Goodwill, Impaired, Accumulated Impairment Loss [Abstract]
Goodwill gross	$ 150,603,000	$ 150,603,000		$ 107,779,000	$ 107,779,000	$ 29,575,000	$ 29,575,000		$ 13,249,000	$ 13,249,000
Goodwill accumulated impairment	(13,249,000)	(13,249,000)		0	0	0	0		(13,249,000)	(13,249,000)
Goodwill	137,354,000	137,354,000		107,779,000	107,779,000	29,575,000	29,575,000		0	0
Number of Reportable Operating Segments	3	3	3
Goodwill, Impairment Loss								$ 13,249,000