Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Oct. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Short-term borrowings	$ 45.2		$ 162.8
Long-term Debt Types [Abstract]
Capital leases	51.7		29.4	$ 18.9
Total long-term debt	1,191.5		280.4
Total Debt	1,236.7		443.2
Long Term Debt By Current And Noncurrent [Abstract]
Current liabilities	97.1		195.6
Noncurrent liabilities	1,139.6		247.6
Term Loan A | Senior Secured Credit Facility
Long-term Debt Types [Abstract]
Long-term Debt	$ 491.4		0.0
Long-term Debt, Gross		$ 500.0
Interest Rate And Other Disclosures [Abstract]
Effective interest rate	3.30%
Unamortized debt cost	$ 2.3
Senior unsecured notes | Six hundred million senior unsecured notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.625%
Long-term Debt Types [Abstract]
Long-term Debt	$ 591.2		0.0
Long-term Debt, Gross		$ 600.0
Interest Rate And Other Disclosures [Abstract]
Effective interest rate	4.60%
Unamortized debt cost	$ 8.8
Revolving Credit Facility
Long-term Debt Types [Abstract]
Debt	0.0		$ 55.8
Interest Rate And Other Disclosures [Abstract]
Average interest rate			1.80%
Private Placement Notes
Long-term Debt Types [Abstract]
Long-term Debt, Gross	0.0		$ 85.6
Interest Rate And Other Disclosures [Abstract]
Unamortized debt cost			$ 0.1
Private Placement Notes | Private Placement Notes Series A
Interest Rate And Other Disclosures [Abstract]
Average interest rate			4.60%
Private Placement Notes | Private Placement Notes Series B
Interest Rate And Other Disclosures [Abstract]
Average interest rate			5.20%
Term Loan
Long-term Debt Types [Abstract]
Long-term Debt, Gross	0.0		$ 65.6
Interest Rate And Other Disclosures [Abstract]
Effective interest rate			2.50%
Unamortized debt cost			$ 0.2
Other Non-US Dollar-denominated Facilities
Long-term Debt Types [Abstract]
Debt	$ 12.0		$ 6.4
Interest Rate And Other Disclosures [Abstract]
Average interest rate	4.40%		6.90%
Capital leases
Long-term Debt Types [Abstract]
Capital leases	$ 96.9		$ 67.0
Interest Rate And Other Disclosures [Abstract]
Average interest rate	5.00%		4.20%
Uncommitted Credit Facilities
Debt Instrument [Line Items]
Short-term borrowings	$ 0.0		$ 108.3
Interest Rate And Other Disclosures [Abstract]
Short-term borrowings interest rate			1.70%
Restricted Cash Borrowings
Debt Instrument [Line Items]
Short-term borrowings	$ 27.0		$ 22.3
Interest Rate And Other Disclosures [Abstract]
Short-term borrowings interest rate	0.00%		0.50%
Other
Debt Instrument [Line Items]
Short-term borrowings	$ 18.2		$ 32.2
Interest Rate And Other Disclosures [Abstract]
Short-term borrowings interest rate	8.90%		8.10%