Pension and Postretirement Plans - Schedule of Pension and Postretirement Costs (Benefits) (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 07, 2021	Sep. 30, 2022	Sep. 07, 2021	Sep. 30, 2022
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 0.0	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Other components of pension and postretirement benefit plans expense:
Interest cost on projected benefit obligation	0.9	2.7	4.2	10.2	11.9
Expected return on plan assets	(2.1)	(5.2)	(6.6)	(19.9)	(20.9)
Amortization of:
Prior service benefit	0.0	0.0	0.0	0.0	0.0
Actuarial loss	0.0	4.5	0.0	16.0	0.0
Pension / postretirement (benefit) cost	(1.2)	2.0	(2.4)	6.3	(9.0)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	0.0	0.1	0.4	0.3	0.6
Other components of pension and postretirement benefit plans expense:
Interest cost on projected benefit obligation	0.1	0.5	1.7	1.8	3.1
Expected return on plan assets	0.0	0.0	0.0	0.0	0.0
Amortization of:
Prior service benefit	0.0	(0.4)	0.0	(1.7)	0.0
Actuarial loss	0.0	0.0	0.0	0.0	0.0
Pension / postretirement (benefit) cost	$ 0.1	$ 0.2	$ 2.1	$ 0.4	$ 3.7