Intangible Assets and Goodwill (Details) (USD $)	3 Months Ended		9 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2013	Apr. 30, 2012	Jul. 31, 2012
Intangible assets with finite lives:
Amortization expense	$ 2,598,000	$ 2,279,000	$ 7,438,000	$ 6,846,000
Gross	107,575,000		107,575,000		97,532,000
Accumulated Amortization	(42,837,000)		(42,837,000)		(35,656,000)
Net	64,738,000		64,738,000		61,876,000
Intangible assets with indefinite lives:
Trademarks and trade names	9,427,000		9,427,000		9,435,000
Total intangible assets
Gross	117,002,000		117,002,000		106,967,000
Accumulated Amortization	(42,837,000)		(42,837,000)		(35,656,000)
Net	74,165,000		74,165,000		71,311,000
Estimated annual amortization expense of intangible assets for next five years
Remainder of fiscal year	2,597,000		2,597,000
Fiscal 2014	10,099,000		10,099,000
Fiscal 2015	9,840,000		9,840,000
Fiscal 2016	6,600,000		6,600,000
Fiscal 2017	6,024,000		6,024,000
Fiscal 2018	5,747,000		5,747,000
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	68,754,000		68,754,000		60,271,000
Accumulated Amortization	(24,748,000)		(24,748,000)		(20,421,000)
Net	44,006,000		44,006,000		39,850,000
Total intangible assets
Accumulated Amortization	(24,748,000)		(24,748,000)		(20,421,000)
Technology
Intangible assets with finite lives:
Gross	21,054,000		21,054,000		20,797,000
Accumulated Amortization	(9,094,000)		(9,094,000)		(7,590,000)
Net	11,960,000		11,960,000		13,207,000
Total intangible assets
Accumulated Amortization	(9,094,000)		(9,094,000)		(7,590,000)
Brand names
Intangible assets with finite lives:
Gross	12,758,000		12,758,000		11,945,000
Accumulated Amortization	(7,777,000)		(7,777,000)		(6,778,000)
Net	4,981,000		4,981,000		5,167,000
Total intangible assets
Accumulated Amortization	(7,777,000)		(7,777,000)		(6,778,000)
Non-compete agreement
Intangible assets with finite lives:
Gross	3,359,000		3,359,000		3,147,000
Accumulated Amortization	(655,000)		(655,000)		(404,000)
Net	2,704,000		2,704,000		2,743,000
Total intangible assets
Accumulated Amortization	(655,000)		(655,000)		(404,000)
Patents and other registrations
Intangible assets with finite lives:
Gross	1,650,000		1,650,000		1,372,000
Accumulated Amortization	(563,000)		(563,000)		(463,000)
Net	1,087,000		1,087,000		909,000
Total intangible assets
Accumulated Amortization	$ (563,000)		$ (563,000)		$ (463,000)