Retirement Benefits - Components of Net Periodic Benefit Cost for Defined Benefit Plans and Other Postretirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.1	$ 0.2	$ 0.3	$ 0.5
Interest cost	0.2	0.1	0.6	0.4
Net amortization	(0.2)	(0.1)	(0.7)	(0.3)
Net periodic cost	0.1	0.2	0.2	0.6
U.S. | Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.1	0.0	0.1	0.1
Interest cost	0.1	0.1	0.3	0.2
Expected return on plan assets	(0.1)	(0.1)	(0.2)	(0.2)
Net amortization	0.0	0.1	0.1	0.2
Net periodic cost	0.1	0.1	0.3	0.3
Non-U.S. | Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.3	0.5	0.9	1.4
Interest cost	0.6	0.2	2.0	0.7
Expected return on plan assets	(0.4)	(0.4)	(1.2)	(1.0)
Net amortization	(0.1)	0.2	(0.4)	0.6
Net periodic cost	$ 0.4	$ 0.5	$ 1.3	$ 1.7