Segment information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Revenue and Operating Profit [Line Items]
Revenues	$ 1,006.5	$ 953.5	$ 941.4	$ 940.7	$ 968.3	$ 965.5	$ 947.8	$ 884.7	$ 3,842.1	$ 3,766.3	$ 2,976.2
Operating profit	50.7	43.2	30.6	46.7	55.8	66.6	33.6	43.5	171.2	199.5	176.5
Capital expenditures	66.9	47.4	36.7	33.5	75.7	46.6	40.8	28.9	184.5	192.0	137.8
Depreciation									156.6	146.2	117.5
Depreciation and amortization	42.9	41.0	40.6	41.0	40.8	39.0	39.6	37.2	165.5	156.6	126.6
Total assets	2,553.9				2,406.2				2,553.9	2,406.2	2,270.5
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	1,093.7				1,044.4				1,093.7	1,044.4	1,026.4
Revenues									3,842.1	3,766.3	2,976.2
Net Assets Outside Us [Line Items]
Net assets	842.6				802.9				842.6	802.9	775.3
Unconsolidated Equity Affiliates held by International Segment [Abstract]
Carrying value of investments at year end	15.6				12.8				15.6	12.8
Share of earnings of unconsolidated equity affiliates									6.0	4.8	3.9
Europe, Middle East and Africa [Member]
Net Assets Outside Us [Line Items]
Net assets	272.1				283.4				272.1	283.4	288.2
Latin America [Member]
Net Assets Outside Us [Line Items]
Net assets	438.2				376.9				438.2	376.9	346.4
Asia Pacific [Member]
Net Assets Outside Us [Line Items]
Net assets	89.1				85.8				89.1	85.8	82.0
Other Region [Member]
Net Assets Outside Us [Line Items]
Net assets	43.2				56.8				43.2	56.8	58.7
International Segment [Member]
Unconsolidated Equity Affiliates held by International Segment [Abstract]
Carrying value of investments at year end	15.6				12.8				15.6	12.8	11.5
Share of earnings of unconsolidated equity affiliates									6.0	4.8	3.9
Undistributed earnings of equity affiliates included in consolidated retained earrings [Abstract]
Undistributed earnings	8.8				7.1				8.8	7.1	5.7
France [Member]
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	163.5				149.9				163.5	149.9	159.9
Revenues									535.5	545.2	508.6
Mexico [Member]
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	145.3				123.9				145.3	123.9	118.5
Revenues									424.0	415.2	51.7
Brazil [Member]
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	95.6				100.9				95.6	100.9	99.8
Revenues									388.3	386.8	303.3
Canada [Member]
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	90.8				87.3				90.8	87.3	83.6
Revenues									238.7	240.7	185.4
Venezuela [Member]
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	46.7				43.5				46.7	43.5	38.3
Revenues									342.6	269.2	185.9
All Other Segments [Member]
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	348.8				338.1				348.8	338.1	340.9
Revenues									1,206.3	1,175.7	1,008.9
Non Us [Member]
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	890.7				843.6				890.7	843.6	841.0
Revenues									3,135.4	3,032.8	2,243.8
United States [Member]
Long-Lived Assets and Revenues [Line Items]
Long-Lived Assets	203.0				200.8				203.0	200.8	185.4
Revenues									706.7	733.5	732.4
International [Member]
Segment Revenue and Operating Profit [Line Items]
Revenues									2,896.7	2,792.1	2,058.4
Operating profit									227.6	227.9	195.0
Capital expenditures									130.3	140.6	99.7
Depreciation									95.1	91.6	74.5
Amortization									7.2	8.4	8.1
Total assets	1,708.5				1,565.9				1,708.5	1,565.9	1,531.7
North America [Member]
Segment Revenue and Operating Profit [Line Items]
Revenues									945.4	974.2	917.8
Operating profit									32.5	31.4	44.1
Capital expenditures									54.2	51.4	38.1
Depreciation									61.5	54.6	43.0
Amortization									1.7	2.0	1.0
Total assets	480.5				468.6				480.5	468.6	426.8
Segment operating profit [Member]
Segment Revenue and Operating Profit [Line Items]
Operating profit									260.1	259.3	239.1
Total assets	2,189.0				2,034.5				2,189.0	2,034.5	1,958.5
Non Segment [Member]
Segment Revenue and Operating Profit [Line Items]
Operating profit									(88.9)	(59.8)	(62.6)
Total assets	$ 364.9				$ 371.7				$ 364.9	$ 371.7	$ 312.0