Pension and Other Retiree Benefits (Net Periodic Benefit Expense) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension | U.S.
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 1.6	$ 1.4	$ 1.3
Interest cost		6.7	7.1	7.3
Expected return on plan assets		(11.8)	(12.3)	(11.9)
Amortization of net loss (gain)		2.7	2.0	1.8
Amortization of prior service cost		0.4	0.4	0.4
Curtailment gain		0.0	0.0	0.0
Net periodic benefit income(2)	[1]	(0.4)	(1.4)	(1.1)
Pension | International
Defined Benefit Plan Disclosure [Line Items]
Service cost		1.9	1.9	0.8
Interest cost		12.9	13.4	10.3
Expected return on plan assets		(22.7)	(21.8)	(17.6)
Amortization of net loss (gain)		3.4	3.0	2.3
Amortization of prior service cost		0.0	0.0	0.0
Curtailment gain		(0.6)	0.0	0.0
Net periodic benefit income(2)	[1]	(5.1)	(3.5)	(4.2)
Post-retirement
Defined Benefit Plan Disclosure [Line Items]
Service cost		0.1	0.0	0.1
Interest cost		0.2	0.2	0.2
Expected return on plan assets		0.0	0.0	0.0
Amortization of net loss (gain)		(0.4)	(0.4)	(0.4)
Amortization of prior service cost		(0.1)	0.0	0.0
Curtailment gain		0.0	0.0	(0.6)
Net periodic benefit income(2)	[1]	$ (0.2)	$ (0.2)	$ (0.7)

[1] (2)The components, other than service cost, are included in the line "Non-operating pension income" in the Consolidated Statements of Income.