Debt - Components of Debt (Details) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt payable—unconsolidated affiliate		$ 45.6	$ 42.4
Total debt		1,546.5	1,543.9
Debt payable within one year		14.8	20.1
Debt payable after one year		$ 1,531.7	$ 1,523.8
Weighted average interest rates on total debt		4.80%	4.70%
5.125% Senior Notes, Due 2021
Debt Instrument [Line Items]
Interest rate (percent)		5.125%	5.125%
Unamortized discount and debt issuance costs		$ 5.4	$ 5.8
Total debt		694.6	694.2
Term Loan B (USD)
Debt Instrument [Line Items]
Unamortized discount and debt issuance costs		4.1	4.3
Total debt		$ 404.3	$ 404.1
5.625% Senior Notes, Due 2024
Debt Instrument [Line Items]
Interest rate (percent)		5.625%	5.625%
Unamortized discount and debt issuance costs		$ 3.3	$ 3.5
Total debt		296.7	296.5
Term Loan B (EUR)
Debt Instrument [Line Items]
Unamortized discount and debt issuance costs		0.9	1.0
Total debt		98.4	94.0
Other borrowings
Debt Instrument [Line Items]
Total debt	[1]	$ 6.9	$ 12.7

[1] (1) Represents borrowings under various lines of credit and other borrowings, primarily by non-U.S. subsidiaries.