Derivative Instruments - Financial Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	$ 7.8	$ 28.9
Counterparty netting, derivative assets	(0.6)	(0.4)
Net derivative asset position	7.2	28.5
Gross derivative liability position	(24.1)	(7.6)
Counterparty netting, derivative liabilities	0.6	0.5
Net derivative liability position	(23.5)	(7.1)
Total net derivative position	(16.3)	21.4
Accounts Receivable
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	7.8	9.7
Deferred Charges and Other Assets
Derivatives, Financial Assets and Liabilities
Gross derivative asset position		19.2
Accounts Payable
Derivatives, Financial Assets and Liabilities
Gross derivative liability position	(6.6)	(6.6)
Other Noncurrent Obligations
Derivatives, Financial Assets and Liabilities
Gross derivative liability position	(17.5)	(1.0)
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments - Economic
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	0.8	1.1
Counterparty netting, derivative assets	(0.6)	(0.4)
Net derivative asset position	0.2	0.7
Gross derivative liability position	(3.3)	(5.7)
Counterparty netting, derivative liabilities	0.6	0.5
Net derivative liability position	(2.7)	(5.2)
Total net derivative position	(2.5)	(4.5)
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments - Economic | Accounts Receivable
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	0.8	1.1
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments - Economic | Accounts Payable
Derivatives, Financial Assets and Liabilities
Gross derivative liability position	(3.3)	(5.7)
Foreign Exchange Forward Contracts | Designated as Hedging Instrument
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	0.4
Net derivative asset position	0.4
Gross derivative liability position		(0.5)
Net derivative liability position		(0.5)
Total net derivative position	0.4	(0.5)
Foreign Exchange Forward Contracts | Designated as Hedging Instrument | Accounts Receivable
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	0.4
Foreign Exchange Forward Contracts | Designated as Hedging Instrument | Accounts Payable
Derivatives, Financial Assets and Liabilities
Gross derivative liability position		(0.5)
Interest Rate Swap
Derivatives, Financial Assets and Liabilities
Gross derivative liability position	(7.3)	(1.4)
Net derivative liability position	(7.3)	(1.4)
Total net derivative position	(7.3)	(1.4)
Interest Rate Swap | Accounts Payable
Derivatives, Financial Assets and Liabilities
Gross derivative liability position	(3.3)	(0.4)
Interest Rate Swap | Other Noncurrent Obligations
Derivatives, Financial Assets and Liabilities
Gross derivative liability position	(4.0)	(1.0)
Cross Currency Swap
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	6.6	27.8
Net derivative asset position	6.6	27.8
Gross derivative liability position	(13.5)
Net derivative liability position	(13.5)
Total net derivative position	(6.9)	27.8
Cross Currency Swap | Accounts Receivable
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	6.6	8.6
Cross Currency Swap | Deferred Charges and Other Assets
Derivatives, Financial Assets and Liabilities
Gross derivative asset position		$ 19.2
Cross Currency Swap | Other Noncurrent Obligations
Derivatives, Financial Assets and Liabilities
Gross derivative liability position	$ (13.5)