Allowance for Uncollectible Accounts Receivables (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at end of period	$ 2,700	$ 3,200
Allowance for uncollectible accounts receivable
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	3,237	4,788	13,939
Additions and adjustments charged to costs and expenses	1,770	564	5,179
Additions/(Reductions) charged to other accounts			(6,428)
Write-offs	(2,290)	(2,115)	(7,902)
Balance at end of period	$ 2,717	$ 3,237	$ 4,788