Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Employee Benefit Plans [Abstract]
Maximum percent of gross wages employees may contribute	75.00%
Matching contributions	$ 1.2	$ 1.2	$ 1.2
Value of shares of common stock owned by remaining plan participants in deferred compensation plan	$ 0.4	$ 0.4

Value of common stock issued to a trust (for example, a 'rabbi trust') set up specifically to accumulate stock for the sole purpose of distribution to participating employees. This trust does not allow employees to immediately or after a holding period diversify into nonemployer securities. The deferred compensation plan for which this trust is set up must be settled by the delivery of a fixed number of shares of employer stock.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 710

-SubTopic 10

-Section 25

-Paragraph 16

-URI http://asc.fasb.org/extlink&oid=6409836&loc=d3e19833-108362

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 97-14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant