Balance Sheet Details - Components of Property Plant and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	May 31, 2013	Aug. 31, 2012
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 370,908	$ 365,389
Accumulated depreciation	(261,873)	(252,198)
Net property, plant and equipment	109,035	113,191
Land [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	11,713	11,623
Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	352,144	346,087
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 7,051	$ 7,679