Retirement Benefits - Components of Net Periodic Benefit Cost for Defined Benefit Plans and Other Postretirement Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.1	$ 0.1
Interest cost	0.2	0.2
Net amortization	(0.2)	(0.2)
Net periodic cost	0.1	0.1
U.S. | Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.0	0.0
Interest cost	0.1	0.1
Expected return on plan assets	(0.1)	(0.1)
Net amortization	0.1	0.1
Net periodic cost	0.1	0.1
Non-U.S. | Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.4	0.3
Interest cost	0.6	0.7
Expected return on plan assets	(0.4)	(0.4)
Net amortization	0.0	(0.2)
Net periodic cost	$ 0.6	$ 0.4