Benefit Plans, Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service cost	$ 4.5	$ 6.6	$ 7.7
Interest cost	16.0	11.0	7.9
Expected return on plan assets	(17.8)	(21.5)	(22.0)
Recognized net actuarial (gain) loss	2.9	5.3	12.1
Settlement/curtailment (gain) loss	0.1	3.5	3.4
Net periodic benefit cost	5.7	4.9	9.1
Post-Retirement Benefits [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service cost	0.0	0.0	0.1
Interest cost	0.1	0.0	0.1
Expected return on plan assets	0.0	0.0	0.0
Recognized net actuarial (gain) loss	(0.5)	(0.4)	(0.8)
Settlement/curtailment (gain) loss	0.0	0.0	(1.6)
Net periodic benefit cost	$ (0.4)	$ (0.4)	$ (2.2)