Pension and Postretirement Benefits (Components of Net Periodic Benefit) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.6	$ 0.4	$ 1.1	$ 0.9
Interest cost	0.5	0.6	1.0	1.1
Expected return on plan assets	(0.8)	(0.8)	(1.6)	(1.6)
Amortization of prior service cost	(0.2)	(0.2)	(0.4)	(0.4)
Amortization of net gain	0.0	0.0	0.1	0.0
Net periodic expense (benefit)	0.1	0.0	0.2	0.0
Postretirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.0	0.0	0.0	0.0
Interest cost	0.2	0.2	0.3	0.4
Expected return on plan assets	0.0	0.0	0.0	0.0
Amortization of prior service cost	(0.2)	(0.2)	(0.4)	(0.5)
Amortization of net gain	(0.2)	(0.2)	(0.4)	(0.3)
Net periodic expense (benefit)	$ (0.2)	$ (0.2)	$ (0.5)	$ (0.4)