Derivative Financial Instruments and Hedging (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2017	Sep. 30, 2016
Derivatives, Fair Value
Collateral Already Posted	$ 4.2	$ 6.1
Commodity and energy contracts
Derivatives, Fair Value
Derivative, Remaining Maturity	15 months
Commodity Contract
Derivatives, Fair Value
Derivative, Notional Amount	$ 77.1	49.8
Energy Contracts
Derivatives, Fair Value
Derivative, Notional Amount	32.6	23.6
Foreign exchange contracts - Option contracts, net
Derivatives, Fair Value
Derivative, Notional Amount	0.0	0.0
Foreign exchange contracts - Cross-Currency swaps
Derivatives, Fair Value
Derivative, Notional Amount	448.7	0.0
Interest Rate Swap
Derivatives, Fair Value
Derivative, Notional Amount	76.4	77.6
Interest rate swaps - Rate-lock swaps
Derivatives, Fair Value
Derivative, Notional Amount	$ 1,649.3	1,649.3
Foreign exchange contracts - Forward contracts
Derivatives, Fair Value
Derivative, Remaining Maturity	20 months
Derivative, Notional Amount	$ 24.0	0.0
Interest rate swap - Step-up swap
Derivatives, Fair Value
Derivative, Notional Amount	1,000.0	0.0
Other Current Assets | Commodity Contract
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	4.6	0.6
Other Current Assets | Energy Contracts
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	1.6	2.4
Other Current Assets | Foreign Exchange Contract
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	1.8	0.0
Other Assets | Foreign Exchange Contract
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	0.3	0.0
Assets, Total
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	8.3	3.0
Other Current Liabilities | Commodity Contract
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	0.6	3.3
Other Current Liabilities | Energy Contracts
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	0.4	0.2
Other Current Liabilities | Foreign Exchange Contract
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	2.0	0.0
Other Current Liabilities | Interest Rate Swap
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	2.4	2.0
Other Noncurrent Liabilities | Foreign Exchange Contract
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	14.0	0.0
Other Noncurrent Liabilities | Interest Rate Swap
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	199.6	313.2
Liabilities, Total
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	219.0	318.7
Portion Designated as Hedging Instruments | Other Current Assets | Commodity Contract
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	0.0	0.0
Portion Designated as Hedging Instruments | Other Current Assets | Energy Contracts
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	0.0	0.0
Portion Designated as Hedging Instruments | Other Current Assets | Foreign Exchange Contract
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	0.5	0.0
Portion Designated as Hedging Instruments | Other Assets | Foreign Exchange Contract
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	0.3	0.0
Portion Designated as Hedging Instruments | Assets, Total
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	0.8	0.0
Portion Designated as Hedging Instruments | Other Current Liabilities | Commodity Contract
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	0.0	0.0
Portion Designated as Hedging Instruments | Other Current Liabilities | Energy Contracts
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	0.0	0.0
Portion Designated as Hedging Instruments | Other Current Liabilities | Foreign Exchange Contract
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	0.0	0.0
Portion Designated as Hedging Instruments | Other Current Liabilities | Interest Rate Swap
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	0.5	0.0
Portion Designated as Hedging Instruments | Other Noncurrent Liabilities | Foreign Exchange Contract
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	0.0	0.0
Portion Designated as Hedging Instruments | Other Noncurrent Liabilities | Interest Rate Swap
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	2.8	0.0
Portion Designated as Hedging Instruments | Liabilities, Total
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	$ 3.3	$ 0.0