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Derivative Financial Instruments (Details) In Millions, unless otherwise specified	6 Months Ended	3 Months Ended	6 Months Ended							6 Months Ended
	Mar. 31, 2013 Cash flow hedges Interest rate swap agreements USD ($)	Mar. 31, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements USD ($)	Mar. 31, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements USD ($)	Mar. 31, 2013 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in September 2015 USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in September 2015 USD ($)	Mar. 31, 2013 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in December 2014 USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in December 2014 USD ($)	Mar. 31, 2013 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in December 2013 USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in December 2013 USD ($)	Mar. 31, 2013 Derivatives designated as hedging instruments Cash flow hedges Foreign currency options USD ($)	Mar. 31, 2013 Derivatives designated as hedging instruments Cash flow hedges Foreign currency options BRL	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Foreign currency options USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Foreign currency options BRL	Mar. 31, 2013 Derivatives not designated as hedging instruments Foreign currency forward contracts USD for foreign currencies USD ($)	Sep. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts USD for foreign currencies USD ($)	Mar. 31, 2013 Derivatives not designated as hedging instruments Foreign currency forward contracts GBP for BRL USD ($)	Mar. 31, 2013 Derivatives not designated as hedging instruments Foreign currency forward contracts GBP for BRL BRL	Sep. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts GBP for BRL USD ($)	Sep. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts GBP for BRL BRL	Mar. 31, 2013 Derivatives not designated as hedging instruments Option contracts USD ($)	Sep. 30, 2012 Derivatives not designated as hedging instruments Option contracts USD ($)
Derivative financial instruments
Effective portion of derivatives before tax effect	$ 4.7	$ (2.1)	$ (2.9)
Effective portion of derivatives expected to be reclassified from accumulated other comprehensive loss to interest expense	2.7
Notional Amount				250.0	250.0	200.0	200.0	150.0	150.0
Fixed Rate (as a percent)				0.95%	0.95%	0.68%	0.68%	0.55%	0.55%
Notional principal of derivative exchange contracts										1.7	3.4	8.1	16.4
Maximum maturity term										24 months	24 months
Notional principal of derivative contracts - purchase														170.7	60.1	12.0	24.3	4.9	9.7	43.3	0
Notional principal of derivative contracts - sell														$ 273.8	$ 110.2	$ 4.9	9.9			$ 0	$ 17.3

X

- Definition

Aggregate notional amount of foreign currency derivatives to exchange foreign currencies. Notional amount refers to the number of currency units specified in the foreign currency derivative contract.

+ References

No definition available.

+ Details

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X

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

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X

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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X

- Definition

High end period remaining until maturity for the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

+ References

No definition available.

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X

- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 205G

-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 10

-Section 50

-Paragraph 4C

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959



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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44C

-Subparagraph b

-Clause 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.

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- Definition

Aggregate notional amount of foreign currency derivatives to purchase a foreign currency. Notional amount refers to the number of currency units specified in the foreign currency derivative contract.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959



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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959

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- Definition

Aggregate notional amount of foreign currency derivatives to sell a foreign currency. Notional amount refers to the number of currency units specified in the foreign currency derivative contract.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959



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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959

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