Fair Value Of Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	May. 31, 2015	Aug. 31, 2014
Fair Value Disclosure [Line Items]
Cash equivalents carried at cost	$ 33.7	$ 34.4
2013 and 2011 Fixed Rate Notes [Member]
Fair Value Disclosure [Line Items]
Long-term Debt, Fair Value	430.5	437.8
Fixed rate notes, carrying value, including accrued interest	430.5	437.8
2011 Variable Rate Notes [Member]
Fair Value Disclosure [Line Items]
Long-term Debt, Fair Value	11.0	0.0
Fixed rate notes, carrying value, including accrued interest	$ 11.0	$ 0.0

Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

Name:	us-gaap_CashEquivalentsAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant