Debt (Long-term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Capital Lease Obligations	$ 10.2
Long-term Debt, Gross	4,298.5	$ 4,385.8
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	23.4	24.2
Total Long-term Debt	4,275.1	4,361.6
Less: Current portion of long-term debt	(365.4)	(430.6)
Long-term debt	$ 3,909.7	3,931.0
United States 5.0%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	5.00%
Debt instrument, Maturity Year	2018
Capital Lease Obligations	$ 0.5	0.7
Foreign 11.3%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	11.30%
Debt Instrument, Maturity Year Range, Start	2017
Debt Instrument, Maturity Year Range, End	2036
Capital Lease Obligations	$ 9.7	1.1
Debentures 8.75%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	8.75%
Debt instrument, Maturity Year	2021
Senior Notes	$ 18.4	18.4
Series D 7.3%
Debt Instrument [Line Items]
Weighted average interest rate	7.30%
Debt instrument, Maturity Year	2016
Medium-term Notes	$ 0.0	32.1
Series E 7.6%
Debt Instrument [Line Items]
Weighted average interest rate	7.60%
Debt instrument, 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 instrument, Maturity Year	2016
Senior Notes	$ 0.0	350.0
Note 1.2%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	1.20%
Debt instrument, 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 instrument, 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 instrument, 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 instrument, 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 instrument, Maturity Year	2024
Senior Notes	$ 400.0	400.0
Variable-rate industrial revenue bonds .68%
Debt Instrument [Line Items]
Weighted average interest rate	0.68%
Debt Instrument, Maturity Year Range, Start	2035
Debt Instrument, Maturity Year Range, End	2050
Other Long-term Debt	$ 769.9	769.9
Other 1.3%
Debt Instrument [Line Items]
Weighted average interest rate	1.30%
Debt Instrument, Maturity Year Range, Start	2018
Debt Instrument, Maturity Year Range, End	2019
Other Long-term Debt	$ 25.7	34.5
Eurobonds 4.625%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	4.625%
Debt instrument, Maturity Year	2017
Debt Payable In Other Currencies	$ 337.0	335.2
Eurobonds 2.0%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	2.00%
Debt instrument, Maturity Year	2020
Debt Payable In Other Currencies	$ 337.0	335.2
Eurobonds 1.0%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	1.00%
Debt instrument, Maturity Year	2025
Debt Payable In Other Currencies	$ 337.0	335.2
Eurobonds .375%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	0.375%
Debt instrument, Maturity Year	2021
Debt Payable In Other Currencies	$ 393.2	0.0
Other 4.4%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage	4.40%
Debt Instrument, Maturity Year Range, Start	2016
Debt Instrument, Maturity Year Range, End	2022
Debt Payable In Other Currencies	$ 52.9	$ 156.3

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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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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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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Amount of unamortized debt discount (premium) and debt issuance costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts 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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Amount of long-term debt classified as other.

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