Other Postretirement Benefit Plans (Details) - Postretirement Plan - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net periodic benefit credit:
Service Cost	$ 0.0	$ 0.0	$ 0.1	$ 0.1
Interest cost	0.4	0.4	1.1	1.1
Amortization of prior service credit	(2.6)	(2.6)	(7.6)	(7.6)
Net periodic benefit cost (credit)	$ (2.2)	$ (2.2)	$ (6.4)	$ (6.4)