Debt - Summary and Maturities (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2016		Sep. 30, 2015	Sep. 30, 2016		Sep. 30, 2015	Dec. 31, 2015	[1]
Debt and Capital Lease Obligations [Abstract]
Total debt		$ 1,138.9		$ 772.2	$ 1,138.9		$ 772.2
Short-term debt		28.8	[1]	25.5	28.8	[1]	25.5	$ 25.5
Long-term debt		1,110.1	[1]	746.7	1,110.1	[1]	746.7	$ 746.7
Interest Income, Expense and Other Financing Costs
Interest income		0.8		1.3	3.6		4.0
Interest expense and other financing costs		(11.0)		(9.2)	(29.5)		(25.5)
Interest expense and other financing costs, net	[1]	(10.3)		(7.9)	(26.0)		(21.5)
Credit Facility
Debt and Capital Lease Obligations [Abstract]
Total debt		796.0		416.0	796.0		416.0
Term Loans
Debt and Capital Lease Obligations [Abstract]
Total debt		323.0		333.2	323.0		333.2
Capital leases
Debt and Capital Lease Obligations [Abstract]
Total debt		14.3		12.0	14.3		12.0
Other
Debt and Capital Lease Obligations [Abstract]
Total debt		$ 5.6		$ 11.0	$ 5.6		$ 11.0

[1] Amounts may not add due to rounding