Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Trade Accounts Receivable [Roll Forward]
Balance at beginning of the period		$ 18.7	$ 19.3	$ 16.8
Provision charged to expense		3.5	2.7	5.7
Write-offs, net of recoveries		(4.8)	(2.4)	(2.0)
Charged to other accounts	[1]	1.3	(0.9)	(1.2)
Balance at end of the period		$ 18.7	$ 18.7	$ 19.3

[1] Primarily includes the effect of foreign currency translation adjustments for the Company's subsidiaries with functional currencies other than the USD.