Components of Accumulated Other Comprehensive Loss - Reclassifications out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of goods sold	$ 502.8	$ 440.0
Selling, general and administrative expenses	14.7	10.7
Other operating expense, net	0.3	0.3
Income tax effect	(2.9)	(1.0)
Net of tax	34.6	0.3
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gain (loss) on financial instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of goods sold	0.0	0.0
Income tax effect	0.0	0.0
Net of tax	0.0	0.0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Defined benefit plan and other postretirement liabilities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of goods sold	0.6	0.7
Selling, general and administrative expenses	(0.4)	(0.4)
Other operating expense, net	0.4	0.5
Income tax effect	(0.3)	(0.4)
Net of tax	$ 0.3	$ 0.4