Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowances for doubtful accounts receivable:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 4.6	$ 4.7	$ 4.7
Additions / (Reversals) Charged to Costs and Expenses	0.0	1.5	0.8
Deductions	(1.4)	(3.5)	(0.8)
Acquisitions	1.6	1.9	0.0
Balance at End of Year	4.8	4.6	4.7
Allowance for credit memos, returns and cash discounts:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	50.5	45.9	41.5
Additions / (Reversals) Charged to Costs and Expenses	278.0	260.8	249.2
Deductions	(293.5)	(256.3)	(244.8)
Acquisitions	0.1	0.1	0.0
Balance at End of Year	35.1	50.5	45.9
Valuation allowance on deferred tax assets:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	19.4	22.6	22.0
Additions / (Reversals) Charged to Costs and Expenses	0.7	(3.2)	0.6
Deductions	0.0	0.0	0.0
Acquisitions	1.7	0.0	0.0
Balance at End of Year	$ 21.8	$ 19.4	$ 22.6