Fair Value Measurements (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Estimate of Fair Value, Fair Value Disclosure [Member]
Liabilities measured at fair value
Debt Instrument, Fair Value Disclosure	$ (1,784.2)	$ (2,478.3)
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	(1,784.2)	(2,478.3)
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Liabilities measured at fair value
Debt Instrument, Fair Value Disclosure	(2,386.3)	(2,452.5)
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	(2,386.3)	(2,452.5)
Fair Value, Measurements, Recurring [Member]
Assets measured at fair value
Assets measured at fair value	95.6	80.1
Liabilities measured at fair value
Liabilities measured at fair value	(50.4)	(41.9)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Assets measured at fair value	93.3	73.5
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	2.3	6.6
Liabilities measured at fair value
Liabilities measured at fair value	(50.4)	(41.9)
Fair Value, Measurements, Recurring [Member] | Cash and Cash Equivalents [Member]
Assets measured at fair value
Cash and cash equivalents	90.0	70.2
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	90.0	70.2
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
Fair Value, Measurements, Recurring [Member] | Other Current Assets [Member]
Assets measured at fair value
Foreign exchange contracts - current	0.0	1.2
Commodity hedge contracts - current	1.7	3.6
Fair Value, Measurements, Recurring [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Foreign exchange contracts - current	0.0	0.0
Commodity hedge contracts - current	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Foreign exchange contracts - current	0.0	1.2
Commodity hedge contracts - current	1.7	3.6
Fair Value, Measurements, Recurring [Member] | Other Noncurrent Assets [Member]
Assets measured at fair value
Available for sale investments-cash and cash equivalents	3.3	3.3
Commodity hedge contracts - noncurrent	0.6	1.8
Fair Value, Measurements, Recurring [Member] | Other Noncurrent Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Available for sale investments-cash and cash equivalents	3.3	3.3
Commodity hedge contracts - noncurrent	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Other Noncurrent Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Available for sale investments-cash and cash equivalents	0.0	0.0
Commodity hedge contracts - noncurrent	0.6	1.8
Fair Value, Measurements, Recurring [Member] | Accrued Liabilities [Member]
Liabilities measured at fair value
Commodity hedge contracts - current	(38.6)	(36.2)
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
Fair Value, Measurements, Recurring [Member] | Accrued Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities measured at fair value
Commodity hedge contracts - current	(38.6)	(36.2)
Fair Value, Measurements, Recurring [Member] | Other Noncurrent Liabilities [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	(11.8)	(5.7)
Fair Value, Measurements, Recurring [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities measured at fair value
Commodity hedge contracts - noncurrent	$ (11.8)	$ (5.7)
Assets [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 contracts (in hundredths)	1.50%
Liability [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 contracts (in hundredths)	3.50%