Debt (Long-term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2015	Sep. 30, 2014
Debt Instrument [Line Items]
Less: Unamortized discount	$ (6.3)	$ (5.7)
Total Long-term Debt	4,384.7	4,889.8
Less: Current portion of long-term debt	(435.6)	(65.3)
Long-term debt	$ 3,949.1	4,824.5
United States 5.0%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	5.00%
Debt Instruments Maturity Year	2018
Capital Lease Obligations	$ 0.7	1.0
Foreign 7.7%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	7.70%
Debt Instrument, Maturity Year Range, Start	2017
Debt Instrument, Maturity Year Range, End	2021
Capital Lease Obligations	$ 1.1	1.5
Debentures 8.75%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	8.75%
Debt Instruments Maturity Year	2021
Senior Notes	$ 18.4	18.4
Series D 7.3%
Debt Instrument [Line Items]
Weighted average interest rate	7.30%
Debt Instruments Maturity Year	2016
Medium-term Notes	$ 32.1	32.1
Series E 7.6%
Debt Instrument [Line Items]
Weighted average interest rate	7.60%
Debt Instruments Maturity Year	2026
Medium-term Notes	$ 17.2	17.2
Note 2.0%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	2.00%
Debt Instruments Maturity Year	2016
Senior Notes	$ 350.0	350.0
Note 1.2%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	1.20%
Debt Instruments Maturity Year	2018
Senior Notes	$ 400.0	400.0
Note 4.375%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	4.375%
Debt Instruments Maturity Year	2019
Senior Notes	$ 400.0	400.0
Note 3.0%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	3.00%
Debt Instruments Maturity Year	2022
Senior Notes	$ 400.0	400.0
Note 2.75%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	2.75%
Debt Instruments Maturity Year	2023
Senior Notes	$ 400.0	400.0
Note 3.35%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	3.35%
Debt Instruments Maturity Year	2024
Senior Notes	$ 400.0	400.0
Variable-rate industrial revenue bonds 0.01%
Debt Instrument [Line Items]
Weighted average interest rate	0.01%
Debt Instrument, Maturity Year Range, Start	2035
Debt Instrument, Maturity Year Range, End	2050
Other Long-term Debt	$ 769.9	917.1
Other 2.4%
Debt Instrument [Line Items]
Weighted average interest rate	2.40%
Debt Instrument, Maturity Year Range, Start	2015
Debt Instrument, Maturity Year Range, End	2020
Other Long-term Debt	$ 35.0	25.3
Eurobonds 3.875%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	3.875%
Debt Instruments Maturity Year	2015
Debt Payable In Other Currencies	$ 0.0	378.9
Eurobonds 4.625%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	4.625%
Debt Instruments Maturity Year	2017
Debt Payable In Other Currencies	$ 335.2	378.9
Eurobonds 1.0%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	1.00%
Debt Instruments Maturity Year	2025
Debt Payable In Other Currencies	$ 335.2	0.0
Eurobonds 2.0%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	2.00%
Debt Instruments Maturity Year	2020
Debt Payable In Other Currencies	$ 335.2	378.9
CLP Series E bonds 6.3%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	6.30%
Debt Instruments Maturity Year	2030
Debt Payable In Other Currencies	$ 0.0	143.1
Other 6.6%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	6.60%
Debt Instrument, Maturity Year Range, Start	2016
Debt Instrument, Maturity Year Range, End	2022
Debt Payable In Other Currencies	$ 161.0	$ 253.1

Latest year the outstanding debt instruments are required to be repaid

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Earliest year the outstanding debt instruments are required to be repaid

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Year the outstanding debt instruments are required to be repaid

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Debt Payable In Other Currencies

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Weighted average interest rate of long-term debt outstanding.

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Including the current and noncurrent portions, carrying value at the balance sheet date of a financial instrument used to receive debt funding on a regular basis with original maturities ranging from 5-10 years.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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