Retirement Benefits (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Settlement loss (gain)	$ 0.0	$ (64.9)	$ 0.0
Termination benefits			17.4
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	11.9	15.1	12.7
Interest cost on benefits earned in prior years	69.7	68.4	86.3
Expected return on plan assets	(128.2)	(136.4)	(134.5)
Amortization of prior service cost (credit)	0.4	0.6	0.7
Amortization of net actuarial loss	63.5	75.6	74.5
Settlement loss (gain)	29.5	0.0	0.0
Curtailment loss (gain)	0.0	0.0	0.0
Termination benefits	0.0	0.0	10.9
Total retirement benefit expense (income)	46.8	23.3	50.6
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	1.1	1.5	2.3
Interest cost on benefits earned in prior years	7.7	8.0	10.7
Expected return on plan assets	0.0	0.0	0.0
Amortization of prior service cost (credit)	(0.9)	(2.4)	(3.8)
Amortization of net actuarial loss	13.2	13.9	10.8
Settlement loss (gain)	0.0	(64.9)	0.0
Curtailment loss (gain)	0.0	0.0	(0.2)
Termination benefits	0.0	0.0	6.7
Total retirement benefit expense (income)	$ 21.1	$ (43.9)	$ 26.5