Pension and Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pension plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.5	$ 0.4	$ 0.9	$ 0.8
Interest cost	15.3	16.1	30.7	32.1
Expected return on plan assets	(19.9)	(20.0)	(39.8)	(39.9)
Amortization of prior service cost (credit)	(0.1)	0.0	(0.1)	0.0
Amortization of actuarial loss (gain)	(0.3)	(0.6)	(0.6)	(1.2)
Net periodic cost (income)	(4.5)	(4.1)	(8.9)	(8.2)
Postretirement benefit obligations
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.0	0.0	0.0	0.0
Interest cost	0.0	0.0	0.0	0.0
Expected return on plan assets	0.0	0.0	0.0	0.0
Amortization of prior service cost (credit)	(0.1)	(0.1)	(0.2)	(0.2)
Amortization of actuarial loss (gain)	0.0	0.0	0.0	0.0
Net periodic cost (income)	$ (0.1)	$ (0.1)	$ (0.2)	$ (0.2)