Schedule II - Valuation And Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 6.2	$ 5.9	$ 6.0
Charged to Costs and Expenses	2.0	2.1	2.0
Deductions	(1.2)	(1.8)	(2.1)
Balance at End of Period	$ 7.0	$ 6.2	$ 5.9