Fair Value Measurements (Details) $ in Millions	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Estimate of Fair Value, Fair Value Disclosure [Member]
Liabilities measured at fair value
Debt Instrument, Fair Value Disclosure	$ (2,100.2)	$ (2,273.4)
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value, Inputs, Level 1 [Member]
Liabilities measured at fair value
Debt Instrument, Fair Value Disclosure	0.0	0.0
Estimate of Fair Value, Fair Value Disclosure [Member] \| Fair Value, Inputs, Level 2 [Member]
Liabilities measured at fair value
Debt Instrument, Fair Value Disclosure	(2,100.2)	(2,273.4)
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Liabilities measured at fair value
Debt Instrument, Fair Value Disclosure	(2,036.6)	(2,110.1)
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value, Inputs, Level 1 [Member]
Liabilities measured at fair value
Debt Instrument, Fair Value Disclosure	0.0	0.0
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Fair Value, Inputs, Level 2 [Member]
Liabilities measured at fair value
Debt Instrument, Fair Value Disclosure	(2,036.6)	(2,110.1)
Fair Value, Measurements, Recurring [Member]
Assets measured at fair value
Assets measured at fair value	65.8	85.7
Liabilities measured at fair value
Liabilities measured at fair value	(7.0)	(5.7)
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Assets measured at fair value	46.0	38.0
Liabilities measured at fair value
Liabilities measured at fair value	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Assets measured at fair value	19.8	47.7
Liabilities measured at fair value
Liabilities measured at fair value	(7.0)	(5.7)
Fair Value, Measurements, Recurring [Member] \| Cash and Cash Equivalents [Member]
Assets measured at fair value
Cash and cash equivalents	46.0	38.0
Fair Value, Measurements, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Cash and cash equivalents	46.0	38.0
Fair Value, Measurements, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Cash and cash equivalents	$ 0.0	0.0
Measurement Input, Counterparty Credit Risk [Member] \| Maximum [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Benchmark interest rates for asset contracts (in hundredths)	0.02
Benchmark interest rates for liability contracts (in hundredths)	0.03
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Current Assets [Member]
Assets measured at fair value
Commodity hedge contracts - current	$ 0.4	0.2
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Current Assets [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Commodity hedge contracts - current	0.0	0.0
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Current Assets [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Commodity hedge contracts - current	0.4	0.2
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Assets [Member]
Assets measured at fair value
Commodity hedge contracts - noncurrent	1.0	1.7
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Assets [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Commodity hedge contracts - noncurrent	0.0	0.0
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Assets [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Commodity hedge contracts - noncurrent	1.0	1.7
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Accrued Liabilities [Member]
Liabilities measured at fair value
Commodity hedge contracts - current	(0.8)	(0.3)
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Accrued Liabilities [Member] \| Fair Value, Inputs, Level 1 [Member]
Liabilities measured at fair value
Commodity hedge contracts - current	0.0	0.0
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Accrued Liabilities [Member] \| Fair Value, Inputs, Level 2 [Member]
Liabilities measured at fair value
Commodity hedge contracts - current	(0.8)	(0.3)
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Liabilities [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	(0.9)	0.0
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Liabilities [Member] \| Fair Value, Inputs, Level 1 [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	0.0	0.0
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Liabilities [Member] \| Fair Value, Inputs, Level 2 [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	(0.9)	0.0
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Current Assets [Member]
Assets measured at fair value
Commodity hedge contracts - current	16.1	35.2
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Current Assets [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Commodity hedge contracts - current	0.0	0.0
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Current Assets [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Commodity hedge contracts - current	16.1	35.2
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Assets [Member]
Assets measured at fair value
Commodity hedge contracts - noncurrent	2.3	10.6
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Assets [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Commodity hedge contracts - noncurrent	0.0	0.0
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Assets [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Commodity hedge contracts - noncurrent	2.3	10.6
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Accrued Liabilities [Member]
Liabilities measured at fair value
Commodity hedge contracts - current	(3.5)	(4.9)
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Accrued Liabilities [Member] \| Fair Value, Inputs, Level 1 [Member]
Liabilities measured at fair value
Commodity hedge contracts - current	0.0	0.0
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Accrued Liabilities [Member] \| Fair Value, Inputs, Level 2 [Member]
Liabilities measured at fair value
Commodity hedge contracts - current	(3.5)	(4.9)
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Liabilities [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	(1.8)	(0.5)
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Liabilities [Member] \| Fair Value, Inputs, Level 1 [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	0.0	0.0
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Other Non-current Liabilities [Member] \| Fair Value, Inputs, Level 2 [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	$ (1.8)	$ (0.5)

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Value of input used to measure derivative asset.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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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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Fair value of financial and nonfinancial obligations.

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