Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - SEC Schedule, 12-09, Allowance, Credit Loss [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 6.1	$ 6.3	$ 5.9
Additions charged to cost and expenses	8.1	4.5	4.8
Write-offs	(4.2)	(4.9)	(3.7)
Recoveries	1.2	1.6	0.6
Other	(1.6)	(1.4)	(1.3)
Balance at end of year	$ 9.6	$ 6.1	$ 6.3