Retirement Benefits (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost	$ 39.9	$ 35.5	$ 34.5
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	(0.4)	0.0
Service cost - benefits earned during the year	16.4	14.1	20.6
Interest cost on benefits earned in prior years	104.8	116.7	125.4
Expected return on plan assets	(157.9)	(146.9)	(148.7)
Amortization of prior service cost (credit)	0.3	1.3	1.3
Amortization of net actuarial loss	65.9	62.6	65.4
Curtailment loss	0.4	0.0	0.0
Termination benefits	0.0	0.0	1.1
Total retirement benefit expense	29.9	47.8	65.1
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	0.0	0.0
Defined Contribution Plan, Cost	1.0	1.7
Service cost - benefits earned during the year	2.5	2.4	2.6
Interest cost on benefits earned in prior years	12.7	14.6	16.0
Expected return on plan assets	0.0	0.0	(0.1)
Amortization of prior service cost (credit)	(2.9)	(2.9)	(1.7)
Amortization of net actuarial loss	10.6	9.0	9.6
Curtailment loss	0.0	0.0	0.0
Termination benefits	0.0	0.0	2.3
Total retirement benefit expense	$ 22.9	$ 23.1	$ 28.7