Segment information Segment information - Capital Expenditures, Depreciation, Amortization (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment	$ 27.8	$ 20.8
Depreciation and Amortization by Business Segment	33.3	31.3
Amortization of intangible assets:	0.6	0.9
Total	33.9	32.2
Reportable segments
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment	23.0	18.8
Depreciation and Amortization by Business Segment	29.2	28.4
Reportable segments | North America
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment	13.2	10.3
Depreciation and Amortization by Business Segment	16.7	16.5
Reportable segments | South America
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment	5.0	2.6
Depreciation and Amortization by Business Segment	5.2	4.4
Amortization of intangible assets:	0.5	0.5
Reportable segments | Rest of World
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment	4.8	5.9
Depreciation and Amortization by Business Segment	7.3	7.5
Amortization of intangible assets:	0.1	0.4
Corporate items
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment	4.3	1.8
Depreciation and Amortization by Business Segment	2.8	2.8
Venezuela | Other items not allocated to segments
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment	0.5	0.2
Depreciation and Amortization by Business Segment	0.4	0.1
Reorganization and Restructuring 2016 | Other items not allocated to segments
Segment Reporting Information [Line Items]
Depreciation and Amortization by Business Segment	$ 0.9	$ 0.0