Inventories - Components of Inventory (Detail) (USD $)
In Thousands, unless otherwise specified
Aug. 31, 2012
Aug. 31, 2011
Inventory Disclosure [Abstract]    
Raw materials $ 19,773 $ 14,799
Work in progress 1,542 1,752
Finished goods 22,357 16,182
Total inventories $ 43,672 $ 32,733