Post Employment Plans - Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 151.9	$ 162.5
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1.1	1.9
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	100.9	109.8
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	49.9	50.8	$ 43.4
Equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	16.3	19.2
Equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.1	0.1
Equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	16.2	19.1
Equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	29.6	32.0
Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1.0	1.8
Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	28.6	30.2
Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	49.9	50.8
Insurance contracts | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Insurance contracts | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Insurance contracts | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	49.9	50.8
Absolute return fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	50.5	54.5
Absolute return fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Absolute return fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	50.5	54.5
Absolute return fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	5.6	6.0
Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	5.6	6.0
Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 0.0	$ 0.0