Supplemental Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Financial Information [Abstract]
Maintenance and repair costs	$ 42.5	$ 41.4	$ 42.2
Research and development costs	17.4	17.8	18.7
Advertising costs	6.0	5.4	5.5
Interest income	(1.8)	(1.0)	(0.6)
Foreign currency transaction (gain)/loss, net of hedging activity	(0.6)	(9.4)	13.8
Other		(0.8)	4.6
Total	$ (2.4)	$ (11.2)	$ 17.8