Pensions and Other Postretirement Benefits (Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension and other postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7.0	$ 9.5	$ 21.2	$ 28.5
Interest cost	18.3	10.3	54.8	31.1
Expected return on plan assets	(16.4)	(16.5)	(49.2)	(49.7)
Amortization of prior service costs	0.1	0.1	0.1	0.2
Recognized net actuarial (gains)/losses	(4.9)	0.0	(14.9)	0.1
Net periodic benefit cost	1.0	3.4	13.3	10.2
Defined Benefit Plan, Other Cost (Credit)	(3.1)	0.0	1.3	0.0
Defined Benefit Plan Items | Reclassification out of Accumulated Other Comprehensive Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service costs		$ (0.1)		$ (0.2)
Defined Benefit Plan Items | Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension and other postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service costs	$ 0.1		$ 0.1