Segment information - Revenue And Operating Profits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 879.1	$ 788.4
Operating Profit	64.8	70.9
Foreign currency transaction gains	2.8	(0.3)
Reportable segments
Segment Reporting Information [Line Items]
Revenues	853.3	740.3
Operating Profit	101.8	74.8
Corporate expenses
Segment Reporting Information [Line Items]
General, administrative and other expenses	(31.1)	(19.2)
Foreign currency transaction gains	(0.5)	(1.2)
Reconciliation of segment policies to GAAP	1.3	(0.9)
Other items not allocated to segments
Segment Reporting Information [Line Items]
Acquisitions and dispositions, Revenues	0.0	0.0
Reorganization and Restructuring	(3.7)	(4.1)
Acquisitions and dispositions, Operating profit	(6.5)	0.4
Other items not allocated to segments | Venezuela operations
Segment Reporting Information [Line Items]
Revenues	25.8	48.1
Operating Profit	3.5	21.1
North America | Reportable segments
Segment Reporting Information [Line Items]
Revenues	320.1	304.6
Operating Profit	20.6	10.2
South America | Reportable segments
Segment Reporting Information [Line Items]
Revenues	254.8	202.2
Operating Profit	55.6	39.2
Rest of World | Reportable segments
Segment Reporting Information [Line Items]
Revenues	278.4	233.5
Operating Profit	$ 25.6	$ 25.4