Retirement Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Components of net periodic benefit cost (credit):
Recognition of net actuarial losses	$ 2.6	$ 0.9
Pension Plan
Components of net periodic benefit cost (credit):
Service cost	2.3	3.0
Interest cost	5.6	5.5
Expected return on plan assets	(7.7)	(8.6)
Amortization of prior service cost	0.3	0.3
Recognition of net actuarial losses	2.6	0.9
Net periodic benefit cost (credit)	3.1	1.1
Pension Plan | U.S. Plans
Components of net periodic benefit cost (credit):
Service cost	1.9	2.5
Interest cost	4.1	4.4
Expected return on plan assets	(5.2)	(6.1)
Amortization of prior service cost	0.3	0.3
Recognition of net actuarial losses	2.6	0.9
Net periodic benefit cost (credit)	3.7	2.0
Pension Plan | International Plans
Components of net periodic benefit cost (credit):
Service cost	0.4	0.5
Interest cost	1.5	1.1
Expected return on plan assets	(2.5)	(2.5)
Amortization of prior service cost	0.0	0.0
Recognition of net actuarial losses	0.0	0.0
Net periodic benefit cost (credit)	$ (0.6)	$ (0.9)