Retirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Components of net periodic benefit cost:
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	$ 0.0	$ (2.4)	$ 0.0	$ (2.2)
Pension Plan [Member]
Components of net periodic benefit cost:
Service cost	3.0	3.6	6.0	7.2
Interest cost	7.8	7.6	15.7	15.4
Expected return on plan assets	(9.0)	(10.2)	(18.0)	(20.5)
Amortization of prior service cost	0.5	0.4	0.9	0.8
Net periodic benefit cost	2.3	(1.0)	4.6	0.5
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	0.0	(2.4)	0.0	(2.4)
Pension Plan [Member] | Foreign Plan [Member]
Components of net periodic benefit cost:
Service cost	0.4	0.4	0.8	0.8
Interest cost	1.8	1.8	3.7	3.7
Expected return on plan assets	(2.6)	(2.9)	(5.2)	(5.9)
Amortization of prior service cost	0.1	0.0	0.1	0.0
Net periodic benefit cost	(0.3)	(0.7)	(0.6)	(1.4)
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	0.0	0.0	0.0	0.0
Pension Plan [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer			34.0
Components of net periodic benefit cost:
Service cost	2.6	3.2	5.2	6.4
Interest cost	6.0	5.8	12.0	11.7
Expected return on plan assets	(6.4)	(7.3)	(12.8)	(14.6)
Amortization of prior service cost	0.4	0.4	0.8	0.8
Net periodic benefit cost	2.6	(0.3)	5.2	1.9
Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year	24.0		24.0
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	$ 0.0	$ (2.4)	$ 0.0	$ (2.4)