Retirement Benefit Plans (Details) - Pension Plan [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Components of net periodic benefit cost:
Service cost	$ 3.6	$ 3.5
Interest cost	7.8	8.0
Expected return on plan assets	(10.3)	(9.7)
Amortization of prior service cost	0.4	0.3
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	0.0	4.4
Net periodic benefit cost	1.5	6.5
Foreign Plan [Member]
Components of net periodic benefit cost:
Service cost	0.4	0.4
Interest cost	1.9	1.8
Expected return on plan assets	(3.0)	(2.7)
Amortization of prior service cost	0.0	0.0
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	0.0	0.0
Net periodic benefit cost	(0.7)	(0.5)
Domestic Plan [Member]
Components of net periodic benefit cost:
Service cost	3.2	3.1
Interest cost	5.9	6.2
Expected return on plan assets	(7.3)	(7.0)
Amortization of prior service cost	0.4	0.3
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	0.0	4.4
Net periodic benefit cost	$ 2.2	$ 7.0