Schedule II - Valuation And Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 103.5	$ 89.7	$ 77.0
Charged to costs & expenses	32.9	32.5	25.2
Impact of currency	4.5	(0.6)	(6.3)
Charged to other accounts	3.5	2.3	21.1
Write-offs, write-downs & deductions	(26.2)	(20.4)	(27.3)
Balance at end of period	$ 118.2	$ 103.5	$ 89.7