Balance Sheet Details - Components of Property, Plant and Equipment (Detail) (USD $)
In Thousands, unless otherwise specified
May 31, 2014
Aug. 31, 2013
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 384,790 $ 377,045
Accumulated depreciation (273,029) (264,904)
Net property, plant and equipment 111,761 112,141
Land and land improvements [Member]
   
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 12,159 11,881
Plant and equipment [Member]
   
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 363,974 359,909
Construction in progress [Member]
   
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 8,657 $ 5,255