Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Intangible Assets by Major Class [Line Items]
Cost	$ 47,208	$ 47,208
Accumulated Amortization	12,868	9,805
Net	34,340	37,403
Developed Technology Rights
Intangible Assets by Major Class [Line Items]
Cost	12,191	12,191
Accumulated Amortization	4,974	3,762
Net	7,217	8,429
Customer Relationships
Intangible Assets by Major Class [Line Items]
Cost	25,440	25,440
Accumulated Amortization	7,824	5,973
Net	17,616	19,467
Trade Names
Intangible Assets by Major Class [Line Items]
Cost	7,607	7,607
Net	7,607	7,607
Order or Production Backlog
Intangible Assets by Major Class [Line Items]
Cost	70	70
Accumulated Amortization	70	70
In Process Research And Development
Intangible Assets by Major Class [Line Items]
Cost	1,900	1,900
Net	$ 1,900	$ 1,900