Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jul. 31, 2012
Intangible Assets by Major Class [Line Items]
Cost	$ 47,138	$ 47,138
Accumulated Amortization	14,330	12,798
Net	32,808	34,340
Developed Technology Rights
Intangible Assets by Major Class [Line Items]
Cost	12,191	12,191
Accumulated Amortization	5,580	4,974
Net	6,611	7,217
Customer Relationships
Intangible Assets by Major Class [Line Items]
Cost	25,440	25,440
Accumulated Amortization	8,750	7,824
Net	16,690	17,616
Trade Names
Intangible Assets by Major Class [Line Items]
Cost	7,607	7,607
Net	7,607	7,607
In Process Research And Development
Intangible Assets by Major Class [Line Items]
Cost	1,900	1,900
Net	$ 1,900	$ 1,900