Pension and Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension Benefits
Components of net periodic benefit cost
Service costs	$ 0.9	$ 1.1	$ 3.4	$ 3.3
Interest costs	0.9	0.4	2.6	1.3
Expected return on plan assets	(2.5)	(3.2)	(7.5)	(9.7)
Recognized net actuarial loss	0.9	0.0	2.7	0.0
Net periodic benefit expense (income)	0.2	(1.7)	1.2	(5.1)
Postretirement Benefits
Components of net periodic benefit cost
Service costs	0.0	0.0	0.0	0.0
Interest costs	0.0	0.0	0.2	0.1
Expected return on plan assets	0.0	0.0	(0.1)	(0.2)
Recognized net actuarial loss	0.1	0.1	0.2	0.2
Net periodic benefit expense (income)	$ 0.1	$ 0.1	$ 0.3	$ 0.1