Employee Benefit And Cash Incentive Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Defined Contribution Plans [Line Items]
Employer contributions	$ 1.9	$ 1.7	$ 1.6
Incentive bonus expense	$ 6.7	$ 4.9	$ 5.4
Maximum [Member]
Defined Contribution Plans [Line Items]
Employer contributions, percentage	6.00%

The increase in the fair value of plan assets from contributions made by the employer.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration