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Operations by Segment - Additional Information (Detail) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) Segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reporting segments | Segment									2
Sales to a largest customer	$ 768.6	$ 749.9	$ 738.2	$ 740.0	$ 698.1	$ 683.9	$ 667.0	$ 636.9	$ 2,996.7	$ 2,685.9	$ 2,536.5
Provisional Income tax expense	$ 81.8								81.8
North America | Geographic Concentration Risk | Customer one
Segment Reporting Information [Line Items]
Sales to a largest customer									361.4	311.5	301.7
North America | Geographic Concentration Risk | Customer Two
Segment Reporting Information [Line Items]
Sales to a largest customer									$ 335.2	$ 280.8	$ 287.0
North America | Sales Revenue, Goods, Net | Geographic Concentration Risk | Customer one
Segment Reporting Information [Line Items]
Concentration Risk, Percentage									12.00%	12.00%	12.00%
North America | Sales Revenue, Goods, Net | Geographic Concentration Risk | Customer Two
Segment Reporting Information [Line Items]
Concentration Risk, Percentage									11.00%	11.00%	11.00%

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Tax Cuts and Jobs Act of 2017, incomplete accounting, provisional income tax expense (benefit).

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