Summary of Significant Accounting Policies (Pension Income and Other Postretirement Benefits Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amounts recorded in Cost of sales	$ 1,386.6	$ 1,180.1	$ 1,075.7
Amounts recorded in SG&A expenses	176.1	152.3	134.2
Amounts recorded in Other components of pension income and other postretirement benefits expenses, net	$ (8.8)	(6.4)	(6.2)
Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amounts recorded in Cost of sales		(1.8)	(1.8)
Amounts recorded in SG&A expenses		(0.6)	(0.6)
Amounts recorded in Other components of pension income and other postretirement benefits expenses, net		6.4	6.2
Total pension income and other postretirement benefits expense, net		$ 4.0	$ 3.8