Retirement Benefits - Components of Net Periodic Benefit Cost for Defined Benefit Plans and Other Postretirement Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits | U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.1	$ 0.1	$ 0.1
Interest cost	0.4	0.2	0.3
Expected return on plan assets	(0.2)	(0.2)	(0.9)
Settlement (gain) loss recognized	0.0	0.0	10.5
Net amortization	0.1	0.3	0.4
Net periodic cost	0.4	0.4	10.4
Pension Benefits | Non-U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	1.2	1.8	2.0
Interest cost	2.8	1.0	0.7
Expected return on plan assets	(1.6)	(1.3)	(1.0)
Settlement (gain) loss recognized	(0.1)	0.0	0.0
Net amortization	(0.6)	0.6	2.1
Net periodic cost	1.7	2.1	3.8
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.4	0.7	0.7
Interest cost	0.8	0.5	0.4
Curtailment gain recognized	0.0	0.0	(2.0)
Net amortization	(0.9)	(0.5)	(0.6)
Net periodic cost	$ 0.3	$ 0.7	$ (1.5)