Other Postretirement Benefit Plans - Net Periodic Benefit Cost (Details) - Postretirement Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.2	$ 0.2	$ 0.2
Interest cost	1.4	1.5	2.1
Expected return on plan assets	0.0	0.0	(0.4)
Amortization of prior service credit	(10.1)	(10.1)	(9.8)
Recognition of net actuarial losses (gains)	(13.1)	(4.1)	1.4
Net periodic benefit cost (credit)	$ (21.6)	$ (12.5)	$ (6.5)