Retirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Components of net periodic benefit cost:
Recognition of net actuarial losses (gains)	$ 3.9	$ (11.9)	$ 8.3	$ (3.1)
Pension Plan
Components of net periodic benefit cost:
Service cost	2.9	3.2	8.7	9.4
Interest cost	5.4	6.6	16.5	19.9
Expected return on plan assets	(8.0)	(8.5)	(25.3)	(25.5)
Amortization of prior service cost	0.4	0.4	1.1	1.3
Recognition of net actuarial losses (gains)	3.9	(12.8)	8.3	(4.0)
Net periodic benefit cost (credit)	4.6	(10.2)	9.3	2.0
Curtailment loss	0.0	0.9	0.0	0.9
Pension Plan | Retirement Plan Name, Other [Member]
Components of net periodic benefit cost:
Recognition of net actuarial losses (gains)		0.7
Pension Plan | United States
Components of net periodic benefit cost:
Service cost	2.4	2.7	7.2	8.1
Interest cost	4.3	5.2	13.2	15.7
Expected return on plan assets	(5.5)	(6.3)	(17.7)	(19.0)
Amortization of prior service cost	0.4	0.4	1.0	1.2
Recognition of net actuarial losses (gains)	3.9	(12.8)	8.3	(4.0)
Net periodic benefit cost (credit)	5.5	(9.9)	12.0	2.9
Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year	17.0		17.0
Deferred Compensation Arrangement with Individual, Compensation Expense			9.6
Curtailment loss	0.0	0.9	0.0	0.9
Deferred Compensation Arrangement with Individual, Compensation Expense			9.6
Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year	17.0		17.0
Pension Plan | United States | United States Pension Plan
Components of net periodic benefit cost:
Recognition of net actuarial losses (gains)		12.1		3.3
Pension Plan | Foreign Plan
Components of net periodic benefit cost:
Service cost	0.5	0.5	1.5	1.3
Interest cost	1.1	1.4	3.3	4.2
Expected return on plan assets	(2.5)	(2.2)	(7.6)	(6.5)
Amortization of prior service cost	0.0	0.0	0.1	0.1
Recognition of net actuarial losses (gains)	0.0	0.0	0.0	0.0
Net periodic benefit cost (credit)	(0.9)	(0.3)	(2.7)	(0.9)
Curtailment loss	$ 0.0	$ 0.0	$ 0.0	$ 0.0