Reserve for Inventory Obsolescence (Detail) (Reserve for inventory obsolescence, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2012
Reserve for inventory obsolescence
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 48,168	$ 31,737	$ 24,173
Additions and adjustments charged to costs and expenses	20,515	27,109	27,495
Write-offs	(19,252)	(10,678)	(19,931)
Balance at end of period	$ 49,431	$ 48,168	$ 31,737