Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Millions		6 Months Ended	12 Months Ended
		Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance		$ 2.6	$ 6.3	$ 4.5
Net bad debt expenses	[1]	2.5	1.4	2.1
Additions (deductions)	[2]	(0.6)	(1.5)	(0.3)
Ending Balance		$ 4.5	$ 6.2	$ 6.3

[1] Includes effects of changes in foreign exchange rates

[2] Uncollectible accounts written off, net of recoveries. Also includes effects of changes in foreign exchange rates.