Income Taxes (Unrecognized Tax Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Beginning balance	$ 29.0	$ 32.0	$ 23.8
Additions based on tax positions related to the current year	9.5	6.4	9.1
Additions based on tax positions related to prior years	8.2	1.6	7.1
Reductions based on tax positions related to prior years	(1.4)	(5.0)	(5.5)
Reductions related to settlements with tax authorities	(1.5)	(7.1)	(0.6)
Reductions related to lapses of statute of limitations	(1.1)	(1.2)	(0.9)
Translation (gain)/loss	(0.7)	2.3	(1.0)
Ending balance	$ 42.0	$ 29.0	$ 32.0