Segment information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Mar. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 872.8			$ 905.0
Operating Profit	26.2			58.4
Foreign currency transaction gains (losses)	(1.6)			(3.9)
Reportable segments
Segment Reporting Information [Line Items]
Revenues	872.8			905.0
Operating Profit	89.6			110.8
Corporate expenses
Segment Reporting Information [Line Items]
General, administrative and other expenses	(27.3)			(27.1)
Foreign currency transaction gains (losses)	(2.7)			0.9
Reconciliation of segment policies to GAAP	3.5			0.2
Other items not allocated to segments
Segment Reporting Information [Line Items]
Acquisitions and dispositions, Revenues	0.0			0.0
Reorganization and Restructuring	(5.6)			(3.5)
Acquisitions and dispositions, Operating profit	(19.1)			(17.2)
Reporting compliance	(0.2)			1.4
Other items not allocated to segments | Argentina
Segment Reporting Information [Line Items]
Argentina highly inflationary impact	(2.4)			(4.3)
North America | Reportable segments
Segment Reporting Information [Line Items]
Revenues	444.3			434.5
Operating Profit	33.0			44.0
South America | Reportable segments
Segment Reporting Information [Line Items]
Revenues	197.9			230.3
Operating Profit	41.6			43.0
Rest of World | Reportable segments
Segment Reporting Information [Line Items]
Revenues	230.6			240.2
Operating Profit	15.0			23.8
Internal Loss AR Rebuild
Segment Reporting Information [Line Items]
Revenues			$ 4.0
Internal loss	(9.4)	$ (6.4)	$ (13.7)
Internal Loss AR Rebuild | Other items not allocated to segments
Segment Reporting Information [Line Items]
Revenues	0.0			0.0
Internal loss	$ (9.6)			$ 0.0