Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	$ 4.0	$ 3.6	$ 3.5
Charged to Expense	2.1	3.0	1.8
Deductions	(1.7)	(2.6)	(1.7)
Balance End of Year	4.4	4.0	3.6
Deferred income tax asset valuation allowance:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	0.2	0.2	0.4
Additions	0.0	0.0	0.0
Deductions	0.0	0.0	(0.2)
Balance End of Year	$ 0.2	$ 0.2	$ 0.2