Contingencies And Litigation (Details) (USD $) In Millions, unless otherwise specified	Feb. 29, 2012	Aug. 31, 2011
Contingencies And Litigation [Abstract]
Outstanding letters of credit	$ 8.4	$ 9.5
Discounted present value of future minimum lease payments	$ 4.0

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant