Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 2.1	$ 1.0	$ 1.9
Additions, Charged to Expenses	1.2	1.3	0.3
Additions, Acquired	0.2	0.0	0.0
Deductions, Amounts Written Off	(0.6)	(0.3)	(1.0)
Foreign Exchange	0.0	0.1	(0.2)
Ending Balance	2.9	2.1	1.0
Allowance for Cash Discounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning Balance	4.6	4.6	5.2
Additions, Charged to Expenses	75.5	69.8	68.6
Additions, Acquired	0.7	0.0	0.0
Deductions, Amounts Written Off	(75.8)	(69.8)	(69.2)
Foreign Exchange	0.1	0.0	0.0
Ending Balance	5.1	4.6	4.6
Sales Returns and Allowances
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning Balance	12.1	11.9	11.9
Additions, Charged to Expenses	74.9	56.7	67.4
Additions, Acquired	0.1	0.0	0.0
Deductions, Amounts Written Off	(73.4)	(56.8)	(67.4)
Foreign Exchange	0.2	0.3	0.0
Ending Balance	$ 13.9	$ 12.1	$ 11.9