Financial Instruments (Schedule of Interest Rate Swaps and Cross Currency Interest Rate Swaps) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Jun. 30, 2011 Interest Rate Swaps Contracts [Member]	Jun. 30, 2011 Interest Rate Swaps Contracts [Member] Cash Flow Hedges [Member]	Sep. 30, 2010 Interest Rate Swaps Contracts [Member] Cash Flow Hedges [Member]	Jun. 30, 2011 Interest Rate Swaps Contracts [Member] Fair Value Hedges [Member]	Sep. 30, 2010 Interest Rate Swaps Contracts [Member] Fair Value Hedges [Member]	Jun. 30, 2011 Cross Currency Interest Rate Swaps (Net Investment Hedge) [Member]	Sep. 30, 2010 Cross Currency Interest Rate Swaps (Net Investment Hedge) [Member]
US$ Notional		$ 300.0		$ 595.2	$ 617.0	$ 32.2	$ 32.2
Pay %				LIBOR	LIBOR
Pay %		1.91%				5.54%	5.54%
Average Receive %				3.40%	3.66%	5.50%	5.48%
Average Receive %		LIBOR
Years Average Maturity		5.1	—	4.7	3.8	2.7	3.5
Maximum length of time of hedged exposures, years	5.1

Average Receive Libor

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- Definition

Libor rate

+ Details

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- Definition

Average amount of time remaining before foreign currency exchange rate derivatives mature or expire.

+ Details

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- Definition

Average fixed interest rate that will be received or paid upon exercise of a group of interest rate swaption contracts.

+ Details

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- Definition

Fixed interest rate that will be received or paid upon exercise of the interest rate swaption contract.

+ Details

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- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 45
-Subparagraph b(3)
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6887037&loc=d3e80748-113994

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- Definition

Aggregate notional amount of all derivatives. The notional amount relates to a number of currency units, shares, bushels, pounds, or other units specified in a derivative instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Notional Amount
-URI http://asc.fasb.org/extlink&oid=6519104

+ Details

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