Other Postretirement Benefit Plans (Details) - Postretirement Plan - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net periodic benefit credit:
Interest cost	$ 0.5	$ 0.4
Amortization of prior service credit	(2.1)	(2.5)
Net periodic benefit cost (credit)	$ (1.6)	$ (2.1)