Summary of Pre-Tax Expense Associated with Fair value of Unvested Stock Options and Restricted Stock Awards (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	$ 21.3	$ 15.7	$ 14.4
Cost of Sales
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	2.6	1.8	1.9
Selling, General and Administrative Expenses
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	22.3	16.3	14.1
Unvested Stock Options Fair Value
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	$ 24.9	$ 18.1	$ 16.0