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 at Beginning of Year	$ 11.9	$ 11.2	$ 11.7
Additions Charged to Costs and Expenses	8.1	8.2	8.5
Other Additions (Deductions)	0.0	0.0	0.0
Less Deductions	7.2	7.5	9.0
Balance at End of Year	12.8	11.9	11.2
Insurance Reserves
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	39.0	34.6	31.8
Additions Charged to Costs and Expenses	66.9	68.2	62.3
Other Additions (Deductions)	0.0	0.0	0.0
Less Deductions	68.3	63.8	59.5
Balance at End of Year	$ 37.6	$ 39.0	$ 34.6