Intangible Assets (Detail) (USD $)	9 Months Ended
	Apr. 30, 2015		Jul. 31, 2014
Intangible Assets by Major Class [Line Items]
Cost	$ 83,100,000		$ 82,000,000
Accumulated Amortization	31,400,000		24,600,000
Net	51,738,000		57,366,000
Developed technologies
Intangible Assets by Major Class [Line Items]
Weighted-Average Amortization Period	10 years
Cost	30,300,000		29,600,000
Accumulated Amortization	11,500,000		9,000,000
Net	18,800,000		20,600,000
Customer relationships
Intangible Assets by Major Class [Line Items]
Weighted-Average Amortization Period	13 years
Cost	44,200,000		43,900,000
Accumulated Amortization	19,100,000		15,100,000
Net	25,100,000		28,800,000
Trade names
Intangible Assets by Major Class [Line Items]
Weighted-Average Amortization Period	3 years	[1]
Cost	8,600,000	[1]	8,500,000	[1]
Accumulated Amortization	800,000	[1]	500,000	[1]
Net	$ 7,800,000	[1]	$ 8,000,000	[1]

[1] $7.6 million of trade names are non-amortizable as of April 30, 2015 and July 31, 2014.