Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for doubtful accounts:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	$ 3.6	$ 3.5	$ 3.8
Charged to Expense	3.0	1.8	1.5
Deductions	(2.6)	(1.7)	(1.8)
Balance End of Year	4.0	3.6	3.5
Deferred income tax asset valuation allowance:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	0.2	0.4	0.9
Additions	0.0	0.0	0.0
Deductions	0.0	(0.2)	(0.5)
Balance End of Year	$ 0.2	$ 0.2	$ 0.4