Schedule II - Valuation and Qualifying Accounts (Detail) - Schedule of Doubtful Accounts and Billing Adjustments (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2012		Aug. 31, 2011		Aug. 31, 2010
Balance	$ 1,955	[1]	$ 1,862	[1]	$ 1,712	[1]
Charged to Expense/Against Revenue	1,863	[1]	1,748	[1]	2,903	[1]
Write-offs, Net of Recoveries	1,988	[1]	1,655	[1]	2,753	[1]
Balance	$ 1,830	[1]	$ 1,955	[1]	$ 1,862	[1]

[1] Additions to the allowance for doubtful accounts are charged to bad debt expense. Additions to the allowance for billing adjustments are charged against revenues.