Employees - Fair Value of Pension Assets by Category (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 104.2	$ 102.2	$ 137.9
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	104.2	102.2
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
U.S. companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	7.3	14.3
U.S. companies | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
U.S. companies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	7.3	14.3
U.S. companies | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
International companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3.1	6.3
International companies | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
International companies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3.1	6.3
International companies | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Fixed-income
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	93.8	81.6
Fixed-income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0.0	0.0
Fixed-income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	93.8	81.6
Fixed-income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 0.0	$ 0.0