Accumulated Other Comprehensive Loss - Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax [Abstract]
Net sales	$ 991.2	$ 852.3
Cost of goods sold	(708.3)	(589.7)
Income before income taxes	75.8	90.9
Tax benefit (expense)	(16.0)	(27.0)
Gain (loss) net of tax	(2.2)
Cash flow hedge (loss) gain
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax [Abstract]
Gain (loss) net of tax	(0.2)
Cash flow hedge (loss) gain | Reclassification out of Accumulated Other Comprehensive Income
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax [Abstract]
Cost of goods sold		(0.1)
Prior-service costs
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax [Abstract]
Amortization of defined benefit pension and post retirement benefit items	0.2	0.2
Actuarial gains/(losses)
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax [Abstract]
Amortization of defined benefit pension and post retirement benefit items	(2.8)	(2.8)
Amortization of defined benefit pension and post retirement benefit items
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax [Abstract]
Amortization of defined benefit pension and post retirement benefit items	(2.6)	(2.6)
Tax benefit (expense)	0.6	0.9
Gain (loss) net of tax	(2.0)	(1.7)
AOCI Attributable to Parent
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax [Abstract]
Gain (loss) net of tax	(2.2)	(1.8)
Forward Contracts | Cash flow hedge (loss) gain | Reclassification out of Accumulated Other Comprehensive Income
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax [Abstract]
Net sales	0.0	0.0
Cost of goods sold	(0.2)
Income before income taxes	(0.2)	(0.1)
Tax benefit (expense)	0.0	0.0
Gain (loss) net of tax	$ (0.2)	$ (0.1)