Retirement Benefit Plans - Schedule of Net Periodic Benefit Cost for the Defined Benefit Pension Plans (Details) - Pension Plan - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Components of net periodic benefit cost (credit):
Service cost	$ 0.7	$ 0.7	$ 1.3	$ 1.2
Interest cost	6.8	7.4	13.6	14.3
Expected return on plan assets	(4.3)	(4.9)	(8.6)	(9.5)
Amortization of prior service cost	0.1	0.1	0.2	0.2
Recognition of net actuarial gains	0.0	(1.0)	0.0	(1.9)
Net periodic benefit cost (credit)	3.3	2.3	6.5	4.3
U.S. Plans
Components of net periodic benefit cost (credit):
Service cost	0.3	0.2	0.4	0.4
Interest cost	4.2	4.5	8.5	9.0
Expected return on plan assets	(1.9)	(2.1)	(3.8)	(4.2)
Amortization of prior service cost	0.1	0.1	0.1	0.1
Recognition of net actuarial gains	0.0	(1.0)	0.0	(1.9)
Net periodic benefit cost (credit)	2.7	1.7	5.2	3.4
International Plans
Components of net periodic benefit cost (credit):
Service cost	0.4	0.5	0.9	0.8
Interest cost	2.6	2.9	5.1	5.3
Expected return on plan assets	(2.4)	(2.8)	(4.8)	(5.3)
Amortization of prior service cost	0.0	0.0	0.1	0.1
Recognition of net actuarial gains	0.0	0.0	0.0	0.0
Net periodic benefit cost (credit)	$ 0.6	$ 0.6	$ 1.3	$ 0.9