Segment information - Revenue And Operating Profits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Revenues	$ 805.9	$ 739.5	$ 1,594.3	$ 1,461.3
Operating Profit	48.3	32.2	119.2	55.7
Reportable segments
Segment Reporting Information [Line Items]
Revenues	759.6	716.5	1,499.9	1,405.4
Operating Profit	77.5	52.6	151.7	98.4
Corporate expenses
Segment Reporting Information [Line Items]
General, administrative and other expenses	(18.3)	(16.1)	(37.5)	(33.7)
Foreign currency transaction gains (losses)	1.4	1.4	0.2	2.7
Reconciliation of segment policies to GAAP	(0.9)	1.3	(1.8)	4.5
Other items not allocated to segments
Segment Reporting Information [Line Items]
Acquisitions and dispositions, Revenues	0.0	1.5	0.0	2.3
Reorganization and Restructuring	(5.6)	(2.1)	(9.7)	(8.1)
Acquisitions and dispositions, Operating profit	(1.3)	(6.5)	(0.3)	(12.4)
Other items not allocated to segments | Venezuela operations
Segment Reporting Information [Line Items]
Revenues	46.3	21.5	94.4	53.6
Operating Profit	(4.5)	1.6	16.6	4.3
North America | Reportable segments
Segment Reporting Information [Line Items]
Revenues	311.0	300.8	615.6	593.5
Operating Profit	16.7	3.8	26.9	7.5
South America | Reportable segments
Segment Reporting Information [Line Items]
Revenues	204.6	170.1	406.8	327.1
Operating Profit	35.7	21.3	74.4	45.0
Rest of World | Reportable segments
Segment Reporting Information [Line Items]
Revenues	244.0	245.6	477.5	484.8
Operating Profit	$ 25.1	$ 27.5	$ 50.4	$ 45.9