Intangible Assets (Detail) - USD ($) $ in Thousands		6 Months Ended
		Jan. 31, 2016	Jul. 31, 2015
Intangible Assets by Major Class [Line Items]
Cost		$ 86,600	$ 83,000
Accumulated Amortization		37,000	33,500
Net		$ 49,577	49,499
Developed technologies
Intangible Assets by Major Class [Line Items]
Weighted-Average Amortization Period		10 years
Cost		$ 29,900	30,200
Accumulated Amortization		13,500	12,300
Net		$ 16,400	17,900
Customer relationships
Intangible Assets by Major Class [Line Items]
Weighted-Average Amortization Period		13 years
Cost		$ 47,100	44,200
Accumulated Amortization		22,600	20,300
Net		$ 24,500	23,900
Trade names
Intangible Assets by Major Class [Line Items]
Weighted-Average Amortization Period	[1]	3 years
Cost	[1]	$ 9,600	8,600
Accumulated Amortization	[1]	900	900
Net	[1]	$ 8,700	$ 7,700

[1] $7.6 million of trade names are indefinite-lived as of January 31, 2016 and July 31, 2015, respectively, and $1.1 million and $0.1 million are finite-lived trade names as of January 31, 2016 and July 31, 2015, respectively.