Note 9. Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Nov. 30, 2011	Nov. 30, 2010
Finite-Lived Intangible Assets, Weighted-Average Useful Life	12.0
Finite-Lived Intangible Assets, Amortization Expense	$ 1.9	$ 2.2

Aggregate amount of intangible asset amortization recognized as expense during the period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16323-109275

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