Intangible Assets and Goodwill (Details) (USD $)	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Jul. 31, 2013
Intangible assets with finite lives:
Amortization expense	$ 2,626,000	$ 2,267,000
Gross	110,014,000		110,755,000
Accumulated Amortization	(45,861,000)		(44,213,000)
Net	64,153,000		66,542,000
Intangible assets with indefinite lives:
Trademarks and trade names	9,359,000		9,387,000
Total intangible assets
Gross	119,373,000		120,142,000
Accumulated Amortization	(45,861,000)		(44,213,000)
Net	73,512,000		75,929,000
Low end of range
Intangible assets with finite lives:
Estimated useful lives	2 years
High end of range
Intangible assets with finite lives:
Estimated useful lives	20 years
Weighted average
Intangible assets with finite lives:
Estimated useful lives	11 years
Customer relationships
Intangible assets with finite lives:
Gross	71,846,000		72,142,000
Accumulated Amortization	(26,483,000)		(25,379,000)
Net	45,363,000		46,763,000
Total intangible assets
Accumulated Amortization	(26,483,000)		(25,379,000)
Technology
Intangible assets with finite lives:
Gross	20,509,000		21,006,000
Accumulated Amortization	(9,730,000)		(9,642,000)
Net	10,779,000		11,364,000
Total intangible assets
Accumulated Amortization	(9,730,000)		(9,642,000)
Brand names
Intangible assets with finite lives:
Gross	12,680,000		12,680,000
Accumulated Amortization	(8,392,000)		(8,045,000)
Net	4,288,000		4,635,000
Total intangible assets
Accumulated Amortization	(8,392,000)		(8,045,000)
Non-compete agreement
Intangible assets with finite lives:
Gross	3,159,000		3,159,000
Accumulated Amortization	(603,000)		(541,000)
Net	2,556,000		2,618,000
Total intangible assets
Accumulated Amortization	(603,000)		(541,000)
Patents and other registrations
Intangible assets with finite lives:
Gross	1,820,000		1,768,000
Accumulated Amortization	(653,000)		(606,000)
Net	1,167,000		1,162,000
Total intangible assets
Accumulated Amortization	$ (653,000)		$ (606,000)